To understand the vexed position the modern Republican Party backed itself into with its relentless opposition to the Affordable Care Act, we might listen to one of its most influential analysts. In mid-October, George Will was complaining in his syndicated Washington Post column that neither Barack Obama nor the Tea Party understood that "in Madisonian politics, all progress is incremental." Our constitutional system is "compromise-forcing." Will's great mentor is the leading constitutional thinker among the founders, James Madison. To his regret, Will seemed to believe that both Obama and the base of the Republican Party misunderstood Madison's intentions and his handiwork.

Nine days earlier, though, in the midst of the government shutdown, Will was declaring in an interview with National Public Radio's Steve Inskeep that the possible default of America's incurred debt, for the first time in history, was nothing but politics as usual-and a justified Republican response to dire circumstances. Incrementalism wasn't needed; to carry on the fight was as American as the Civil War. With his trademark mandarin contempt, Will answered Inskeep's question: Weren't Republicans using the shutdown threat as an opportunity to "impose changes they could not get in other ways?"

How does this short-circuit the system? I mean I hear Democrats say the Affordable Care Act is the law, as though we're supposed to genuflect at that sunburst of insight and move on. Well, the Fugitive Slave Act was the law; "separate but equal" was the law. Lots of things were the law and then we changed them. And this is a part of the bruising, untidy, utterly democratic technique for changing laws.

In the months leading up to and immediately following the ACA's start date, Will often drew parallels between the politics of today and those just before the Civil War. Another column compared tussles over immigration reform to the Compromise of 1850, and the one referred to above approvingly quoted the Washington Examiner's Michael Barone in comparing the health-care fight to the mid-1850s struggle over the Kansas-Nebraska Act.

Big stakes. Echoing Will, Representative John Fleming of Louisiana called the ACA "the most dangerous piece of legislation ever passed." The Pulitzer Prize–winning columnist Kathleen Parker, thought to be a moderate conservative frequently critical of the Republican Party, penned the following:

Republicans oppose Obama's policies, not the man, because they believe the president will so inexorably change the structure of our social and economic system by mandating and punishing human behavior that nothing less than individual freedom is at stake. Under present circumstances, this hardly seems delusional.

The allegedly levelheaded Parker thinks it's reasonable to infer that under the Obama presidency, "nothing less than individual freedom is at stake." If you believe what Will, Parker, Fleming, and many of Fleming's congressional colleagues do, comparisons to resisting at gunpoint the return of slaves to their masters-or to take the Slave South's side, sending pro-slavery militia into Kansas-might seem logical. Yet leaving aside controversies about the ACA-faulty computer access, angry insurance holders whose policies have been canceled, millions newly receiving and millions still being denied Medicaid-the law is modest. In every other First World nation, from Australia to Norway, Israel to Canada, France to Japan, the issue of affordable, universal access to comprehensive health care is as quaintly old-hat as black-and-white television.

Only in this country could the parallel between civil war and the opposition to a limited health-insurance law even be raised. The logic can be teased out, but it is a perverse one. For only one major party in American history has exceeded the procedural and policy radicalism of today's GOP: the antebellum Southern Democrats on the eve of the Civil War.

The development of a rearguard, obstructionist Republican Party-an entity so at odds with the party's self-conception as the Constitution's guardian-is not a thunderstorm that has come upon us since the inauguration of Barack Obama. From its antecedents, first in McCarthyism and then in the Goldwater campaign of 1964, the decline accelerated in the last two decades. Since a first major government shutdown in 1995, Republicans have advocated for a trumped-up presidential impeachment and, via the tendentious decision of a partisan Supreme Court, a selected rather than elected president. Until the filibuster was partially contained in November, the Republicans' use of it to create an extra-constitutional, de facto supermajority requirement in the Senate-not only for legislation but for the routine delay and confirmation of presidential appointees and federal judges-dwarfed previous exercise of the gambit in all the years since its inception in 1806.

Partisanship and ideology are not the same thing. Today's GOP has been extreme in both. As Jonathan Chait documented in his prescient 2007 book, The Big Con, the sum total of the GOP's economic and fiscal program has been a desire to keep taxes on the rich as low as possible, cutting programs like food stamps that benefit the poor and boosting those like farm subsidies that benefit the wealthy. Despite their earnest belief (expressed during Democratic presidential administrations) that deficits and debts are, along with the danger of health insurance, the most serious issue facing the country, Republicans grew used to insisting that a time-honored fiscal tool of government-the ability to raise revenue-be forsworn forever.

As evolved over the past two decades, the GOP is something we've not seen before: a Western European–style rightist splinter party trapped within the elephantine body of a conventional major American party.

Its substantive goals are reactionary. The methods it uses to achieve these goals are at the end-reaches of prevailing political norms.

A few apostate conservatives, like David Frum, still consider themselves Republicans but no longer have influence in the party. Other conservative writers who wish to correct course have spent the past several years touting wonkish policy suggestions about, say, prison reform or education or child tax credits. But these earnest conservative policy scientists experimenting in their laboratory remained divorced from the political strategy of the actual Republican Party. Thomas E. Mann and Norman J. Ornstein's It's Even Worse Than It Looks (2012) established that due to what political scientists call asymmetric polarization, congressional Republicans have moved far more to the right over the past several decades than congressional Democrats have moved to the left. Thus both parties, but especially the GOP, have gradually adopted a parliamentary-style approach to politics. In a presidential system with potentially divided poles of governmental legitimation, this has been a recipe for dysfunction. The Republican speaker of the House is no less correct to say that the people have elected him-and legitimated his majority-than is the Democratic president. This structural conflict permits an irresponsible opposition party not only to oppose policy-as happens in the United Kingdom, for example-but to obstruct policy and obscure electoral accountability. Normal governance can be stalled at whim. So, as many political scientists and constitutional scholars acknowledge, we don't have a structural framework that properly enables a party like the modern Republican Party. It is here, nevertheless.

Perhaps, though, following events of the past few months, we have reached a fateful moment: a pause in the march of 21st--century radical Republicanism. Several crucial blows have recently been struck against this unusual party formation. First, the slow-but-steady implementation of the Affordable Care Act. No matter how flawed and controversial, the rollout has transformed continued efforts by Republicans to wreck the bill into an internal measure of radical opposition to all things Obama. Accusing other Republicans of insufficient hatred of the act is still a powerful enforcement mechanism for party discipline, in other words-a kind of "Obamacare McCarthyism" as Talking Points Memo reporter Sahil Kapur has called it. But opposition itself is no longer a practical policy strategy.

In October, Democrats, with a new solidarity led by the president and Senate Majority Leader Harry Reid, defeated Republican attempts to leverage U.S. debt payments as a means to change public policy. Canny Mitch McConnell, the Republicans' leader in the Senate, felt the sting of public backlash and assured that going forward, "a government shutdown is off the table." Following a reopening of the government on terms set by Obama and Reid, Ted Cruz, the purest expression of Tea Party politics, triumphantly returned to his home state of Texas like a winning Super Bowl quarterback. But it is now more doubtful that Cruz can run the same trick play twice.

In late November, Senate Democrats circumscribed the filibuster. In December-likely because of the overdue show of Democratic backbone-the House Republican leadership, led by Paul Ryan, pushed through a minimal budget deal with the Senate Democrats, led by Patty Murray. Frightened and ambitious Republican senators opposed the bargain. But it virtually ensures that government will remain open for the next couple of years.

It might further signal a return to the usual banality of American political culture that the same Newt Gingrich who in 2010 called Obama an exemplar of "Kenyan anti-colonial behavior" posted one of the most perceptive encomiums to Nelson Mandela-and even Ted Cruz flew with the American delegation for Mandela's funeral. On the other hand, Gingrich and Cruz didn't have the last Republican word on Mandela's death, as party leaders had to cope with an outpouring of scurrilous Mandela attacks from a radicalized base.

There is no new normal quite yet. The year 2014 promises more budget fights, and at least a pantomime around not lifting the debt ceiling again, followed by the midterm elections. It is easy to imagine a scenario whereby the Republicans hold the House of Representatives, which will remain heavily gerrymandered in their favor for the rest of this decade, and take the Senate, or just miss doing so.

We would then expect two years of continued entrenched resistance to the Obama administration, but one without the blocking of presidential nominees and the routine threat of government closures. In 2016, we could see whether the Republican rank and file will nominate a shrewd moderate manqué like Chris Christie or ignore their elites altogether and nominate a flamboyant reactionary like Cruz or, in a slightly more placid register, Rand Paul. If any Republican were elected president, we could test in real historical time whether the GOP is more ideologically extreme (opposing a Republican president's efforts at moderation as much as it opposes every policy of Obama's) or more extremely partisan (tolerating policies coming from a Republican administration that it would reflexively fight in a Democratic one).

Meanwhile, at this uncertain interregnum between the recent shutdown and the midterm elections, it is reasonable to take seriously George Will's historical comparisons. For, small hints of moderation aside, it's not well enough understood just how radical the contemporary GOP has become.

But first, let me clarify what I mean by radical. History is contextual, not anachronistic. Simplistic analogies are neither accurate nor illuminating. Even if they wished it-and they don't-modern Republicans could not bring back the days of the Jim Crow South of the late 19th through much of the 20th century, let alone the horrors of slavery. Nor could they put gays back in the closet, prevent married women from having their own credit cards, or even repeal the Clean Air Act. Nor will Medicare and Social Security ever be abolished, even if Republicans (and a few Democrats) might imagine that this is possible. The most extreme challenge to objectionable policies that Republicans could mount at this historical moment would be to permit the government to default unless they receive policy concessions-potentially catastrophic, but not another civil war. No, to be a radical party today does not mean a return to long-discredited and cruel policies. It does mean, however, adopting a logic of implacable resistance. In the early 21st century, "radical" means at the extant limits of today's political discourse, not yesterday's.

It's important to point out that the original United States Constitution made no formal or even implicit acknowledgment of political parties. The Founders, of course, realized that political disagreement-factions-would appear in any polity. But they despised the idea of parties and, within the Constitution, did not anticipate or allow for their development. Alexander Hamilton, brilliant advocate of the most powerful conceivable national government, warned in Federalist No. 22 of the "poison" of a "pertinacious minority"-in this case, seeking the approval of a supermajority of states for national action, regardless of their population.

Madison, the Founders' most influential political theorist, at first expected that the three branches of government, the legislative, executive, and judicial, would divide over their defense of their respective institutional prerogatives. This rational institutional self-interest would produce measured outcomes ultimately satisfactory to the majority yet protective of minorities-ranging from religious heretics to, yes, the white Southern regime of chattel slavery.

Madison the working politician, however, grew to have much less faith in his peers' wisdom than he did in his own. By 1792, it became clear that candidates were running as members of political parties. Madison joined Jefferson as an advocate for the Democratic-Republican Party. It was a development he would not have imagined less than a decade earlier. But parties turned out to be the only way elites could aggregate and exercise power-and prevent other elites from doing the same.

John Aldrich, a leading scholar of the American party system, has noted how early nationalists soon understood that without political parties, majority rule would become unstable. What Aldrich calls the "great principle"-"how powerful and positive the new federal government was to be"-could only be structurally expressed by way of a functional party system that extolled majority rule:

The problem then was how to ensure not just passage of individual bills but achievement of the entire stream of policy-to win on the great principle. Parties, therefore, eventually formed as institutional solutions to the instability of majority rule so that policies chosen or denied would reflect, in the main, just how strong and active the new national government was to be.

As it turned out, the three branches of government today do not divide as Madison anticipated over their defense of their institutional prerogatives. Instead, they divide over which party controls them.

Madison's careful political architecture was to be challenged further in the years leading up to the Civil War. The relationship between the white antebellum South's greatest thinker and politician, John C. Calhoun, and modern conservatism-particularly with regard to racism-has been argued by Sam Tanenhaus in The New Republic. I wish to make a different point: Modern conservatism continues to rely on certain antebellum-era arguments on behalf of states' rights and, also, the intrastate rights of state majorities versus state minorities.

In the decades before the Civil War, the increasingly dominant Southern wing of the Democratic Party agreed about the broad questions of political and economic power. During the 1850s, the issue of slavery destroyed the Whig Party and brought forth the anti-slavery Republican Party (or, at the least, the party opposed to the expansion of slavery). These developments clarified the overwhelmingly pro-slavery position of the Southern Democrats, who argued only over the smartest tactics-whether to stay within or leave the federal union-that would preserve the pervasive privileges and hierarchies of slavery.

Antebellum Southern intellectuals sought to promote and defend their vision of American society by lodging the maximum power possible within the states. Calhoun, as sitting vice president during Andrew Jackson's presidency, had worked, during the 1820s and early 1830s, on refining the doctrine of "nullification" in connection with South Carolina's opposition to congressionally passed tariff laws. Calhoun disagreed that the federal government-whose power to trump the states is enshrined in the supremacy clause of the Constitution (strongly defended by Hamilton in Federalist No. 33)-subsumed, as the clause stated, "under the authority of the United States," a state's right to decide which federal laws (and treaties) are constitutional and which aren't. Calhoun believed that the "mutual negative" of warring interests "forms the constitution." Its essential purpose was to nullify, not ratify.

Nullification was a complex and fascinating doctrine. Crucially, it rejected what many Americans are taught when we are young. It denied that the Supreme Court, via its power of judicial review, has the final say on what makes laws constitutional. "The right of the states … stands on clearer and stronger ground than that of the Court," Calhoun wrote. Nullification also denies that laws duly passed by Congress and signed by the president must be obeyed and enforced by the states.

The larger concept within which Calhoun embedded nullification was the idea of a "concurrent majority."

Unlike the processes leading to a mere "numerical majority" of votes (which Calhoun mocked as the "beau ideal of a perfect government"), a concurrent majority held that all of society's interests, majorities and minorities, be represented in rendering a decision. How precisely this would happen in practice was not spelled out. Unlike the processes leading to a majority of votes in Congress, the Supreme Court, or even a supermajority of states approving a constitutional amendment, a "concurrent majority" required that a majority of states within both the South and North, respectively, approve of a federal law or else it would be voided (precisely contradicting Hamilton in Federalist No. 22). Calhoun carried the idea so far as to propose two presidents, one for the North and one for the South, each able to veto national legislation. In all cases, first a state, then a grouping of states within their respective region, was the unit of democratic will. As Calhoun wrote, each "part" of the whole Union would have "the right of self-protection."

Calhoun's genius was to imagine constitutional law as if the Constitution, like God in some formulations of agnosticism, had created the basis for sovereign government but then left the scene. In its wake, the ultimate right to obey or nullify laws was left to individual states. Thus the Constitution is somehow ancillary to the states that ratified it. A majority of states of the Slave South, regardless of number, population, or policy disputed, can always veto the states of the North.

Calhoun and Madison were both deeply concerned with protecting minority elites, but they disagreed about how that should best be done. As America's founding minority-rights defender, whose authority antebellum Democrats invoked in arguing against federal encroachment, James Madison had mostly been concerned with the protection of particular individuals and factions, not just religious dissidents but propertied men of wealth like himself. These, he feared, might be subject to redistributionist populist demagoguery; a majority coalition of urban laborers and poor farmers, for example, might choose to impose confiscatory taxes upon Madison and wealthy planter and merchant peers or forgive its own debt. Yet as the constitutional scholar Jack Rakove shrewdly argues, Madison also supported (in Federalist No. 10) a large Republic-"the greater number of citizens and extent of territory"-which would better restrain the potential for small, recurrent state majorities to "more easily … concert and execute their plans of oppression."

In fact, while exceedingly careful to argue on behalf of a state-national amalgam, Madison, unlike Calhoun, wished ultimate sovereignty to reside in (we the) people rather than states. As he wrote in Federalist No. 39, "We may define a republic to be … a government which derives all its powers directly or indirectly from the great body of the people." The people might sometimes exercise their power through the states, as when they were to ratify the Constitution. But the people are the foundation of the Republic.

Madison and Hamilton, arguing in The Federalist Papers, again unlike Calhoun, strongly supported judicial review. Madison, "the last Founder," who lived until 1836 (and thus long enough to rebuke Calhoun's theory of nullification during the tariff dispute), continued to insist until the end of his life, against the opposition of Jefferson and others, that the Supreme Court had the final word in adjudicating both federal and state law even when he disagreed with a given Court decision. Again, to quote from Federalist No. 39: "In controversies relating to the boundary between the two jurisdictions [the national government and those of the states] the tribunal which is ultimately to decide, is to be established under the general government [the tribunal being the Supreme Court]."

Madison's insights leave "unanswered a residual question," writes Rakove. How would the rights of minority groups and individuals within the states be protected from an overbearing state majority? Rakove declares the 14th Amendment's equal-protection clause to be an egalitarian antidote for beleaguered state minorities-but conservatives today narrowly read this clause.

Whatever his zigzagging motivations, Madison distinguished between minorities and states. He fought hard but unsuccessfully for the Constitution to include the right of Congress to have a "negative" on any and all state laws, then took the states' side in arguing their right to oppose the Alien and Sedition Acts. He opposed the first national bank but changed his tune on the second one after realizing that having a bank made it easier to fund government, particularly during war. By then, the bank had become an accepted part of American life. Rakove writes, "Madison thus allowed precedents set since 1789 to revise his own original understanding of the Constitution."

Despite the obsessive textualism of modern conservative Republicans-insisting, for example, upon reading the Constitution aloud as if it were holy writ before the beginning of each congressional session-they pick and choose what precepts of Madison, the most influential Founder, they wish to venerate.

They thus simplify one of the most complicated political thinkers in all of modernity.

In one famous early skirmish over slavery, Calhoun and his remarkable protégé James Henry Hammond foreshadowed the frenzied determination of Southern Democrats, 25 years later, to defend and expand slavery into new states. Abolitionists were trying to present petitions to Congress demanding the end of slavery in the District of Columbia. This tactic had been tried before; usually it was summarily ignored. Calhoun, then a senator from South Carolina, decided that quietly strangling this improbable initiative was insufficient. Even the mere acceptance of the petition (not the introduction of a bill to address the issue) would legitimate the abolitionists' position. "Encroachments must be met at the beginning. … In this case … I hold concession or compromise to be fatal," as Calhoun reportedly said in his 1837 speech challenging the petitions. Historian Michael Perman notes that this was not fighting until the "last ditch" but "unyielding resistance at the first ditch."

By the mid-19th century, an insufficient level of agitation had become a major reason the Democrats sought to crush the remaining remnants of the Southern Whig Party. Southern Whigs were determined to defend slavery but could never match the zeal of Southern Democrats. Determination-an affect of angry resistance-came to be seen as a measure of commitment to the cause.

A forerunner of the fearful, reactionary affect of today's Republicans can be seen in this episode. Republican politics today embodies the brilliant axiom of the political scientist and student of American and European conservatism Corey Robin: "Conservatism is: a meditation on-and theoretical rendition of-the felt experience of having power, seeing it threatened, and trying to win it back." The furious reaction-not the initiative-is all.

The rights denied to a minority within a given state today are thankfully not at the world-historic levels absorbed by African American slaves. The logic, however, of a given state minority being denied the right to Medicaid or to marry someone of the same sex-rights available in other states-is not so different. As the mid-20th-century political theorist Louis Hartz observed regarding Calhoun's arguments, there are always "minorities within minorities," so defending the states' minority rights only begs the question of what other minorities needed to be protected. It could, as Hartz mordantly wrote, "unravel itself into separate individuals executing the law of nature for themselves."

So we see, in almost every heavily red state in America today, an expression of the spirit if not the essence of nullification. Rather than concede the direction of humane public policy, most Republicans continue to oppose same-sex marriage and to use majorities in state strongholds to resist the clear direction of the culture and the law on that issue. Republicans could never restore the poll tax or "literacy" tests as a way to deny African Americans the vote. But rather than compete hard for the votes of people of color (as they used to-Richard Nixon received 32 percent of the black presidential vote in 1960, when the GOP was still "the party of Lincoln"), Republicans seek to suppress the vote of Democratic-leaning demographic groups by cutting voting hours. For them, the franchise itself remains controversial. Unlike in other advanced nations, there is no consensus even that voting is an unambiguous democratic good.

Today's Republicans fight from the first ditch.

They are not always successful-but their intensity on many issues dwarfs that of Democrats. We have seen this in the gun lobby's fight against the most minimal attempts to expand background checks. We are often told that we have a "war" between abortion and anti-abortion activists. If so, according to a 2013 Pew poll, there are many more anti-abortion activists who fervently care about the issue than there are abortion-rights advocates who do: 38 percent of those surveyed who wish to overturn Roe v. Wade view abortion as a "critical" issue; only 9 percent of those who support Roe v. Wade believe abortion is critical. Political scientists call this "preference intensity," and it is where the conservatives who control the Republican Party shine.

Many recent Republicans in Congress started as small-business leaders in their local communities, big fish in small ponds. Critical to their political training has been resistance on the state level to national policy impositions regarding guns, immigration, same-sex marriage, health insurance, and reproductive rights. Local moral norms and local leadership must be defended against the interventions of an unsympathetic federal government. But it is important to stress that state minorities do not necessarily share those norms. Surely, for example, impoverished citizens without health insurance might dispute the local moral norms in the 23 Republican states that have rejected the expansion of Medicaid.

Ironically, despite the fears of Madison that wealthy elites would mostly be subject to the irresponsibility of a populist majority, it is these wealthy elites who support Republicans in red states today-while also seeking to maximize their leverage on the national level. As the "red versus blue America" trope has become more deeply embedded in American politics, Democrats and liberals have sought to use constitutional federalism for their own ends in blue states to create quasi-social democracies, respectful of post-1960s feminist and gay-rights movements and greater spending on social services. Republicans and conservatives have sought to use existing state majorities-their still-potent bulwark-to limit the possibilities of political minorities they disdain. In this, they owe more to Calhoun than to Madison.

For now, this is where the GOP remains perched: supported by a minority still numbering many millions, in political control of a number of states in the South, the Mountain West, and parts of the Midwest, and capable of obstructing federal policy-but with hardly any policies for which to advocate.

Regardless of narrow deals that might keep the lights on in Washington over the next couple of years, this particular Republican Party-coherent and reactionary, maximizing its minority leverage nationally and its majority leverage within a number of states-could hunker down for quite some time. The authors of the Constitution never imagined such a political vehicle. Even if the party rebrands in symbolic ways for the sake of the national presidential race, the Republican fight-not merely against the Affordable Care Act but against cosmopolitan modernity-may well go on for a while. It would be fascinating to know what George Will's great teacher, James Madison, would make of it all. Perhaps we already do.