Could the Republicans' congressional strength be the party's greatest weakness as it tries to retake the White House?

That's what Tom Schaller, a political scientist at the University of Maryland Baltimore County, argues in his book The Stronghold, released earlier this year. The national GOP, Schaller says, should now be understood as a "Congress-centered" and "House-heavy" party — and this helps explain why its members have lurched to the right.

Republican members of Congress are setting the national party's agenda, he says. But they're doing it in a way that suits their own specific political needs, rather than those of the party's presidential contenders.

Conservative Republicans in Congress have "quite rationally moved the party ever rightward," Schaller argues

The vast majority of Republican members of Congress, Schaller argues, don't have to appeal to a presidential-year electorate that has more young and racially diverse voters. Instead, for their own benefit, they'd prefer to "double down on the strategy of maximizing the power Republicans derive from their dwindling older, white, male voter base," he writes.

Therefore, on issues like immigration, Republicans have been tailoring their policies and political strategies to win their base — not to get the Republican nominee elected president. "Because conservative Republicans in Congress have paid little electoral price for their policy positions and political choices," Schaller writes, "they quite rationally moved the party ever rightward."

The result is a party that is practically guaranteed control of the House of Representatives but has a harder time winning presidential elections, according to Schaller.

A "feedback loop"

Schaller starts with the famous RNC "autopsy" of the 2012 election results. The March 2013 report recommended that the party "embrace and champion comprehensive immigration reform," and govern in a more "inclusive and appealing manner." GOP governors, the report said, should become the face of the party.

House Republicans didn't listen, to say the least. They refused to act on the bipartisan immigration reform bill passed by the Senate in 2013 — or even to offer an alternative of their own. Despite a seemingly unanimous consensus among party elites that the party had to moderate on the issue to appeal to Latinos, the House didn't budge.

The key thing to understand, Schaller says, is that this decision made perfect sense — House Republicans were responding to the desires of their own electorates. The voters in House Republicans' districts are, in general, whiter, older, and more conservative than the country at large. Perhaps more important, the most conservative voters in these districts are the ones most likely to turn out in GOP primaries. And these voters are more likely to turn out in midterms, too.

"There is simply no serious or significant centrist movement within the Republican Party"

So winning these voters is crucial for House members looking to build their own careers and for building a durable House majority. But responding to these voters is pulling Republicans further and further to the right, in a way that's hurting their national hopes. This, Schaller argues, leads to a "feedback loop" in which Republicans who back very conservative policies keep getting returned to office, despite their policies being out of step with the broader electorate's desires.

The Republican situation, Schaller says, mirrors the troubles the Democratic Party had in the 1980s. National Democrats then were widely perceived as being too beholden to their own liberal interest groups and constituencies, and lost three presidential elections in a row.

But centrist politicians like Bill Clinton and the Democratic Leadership Council "gradually seized control of the party from the failed McGovern-Dukakis liberal wing," Schaller argues, and restored the party's presidential competitiveness. "There is simply no serious or significant centrist movement within the Republican Party, and certainly no center-right analogue to the DLC," he writes.

"You can run the country out of the House"

Schaller goes further than just arguing that the GOP does well in Congress. He also makes the provocative claim that the modern conservative movement might actually view control of the House as more important than the presidency.

In the Reagan years, conservative activists viewed winning the presidency as their most important goal. But after the GOP takeover of Congress in 1994, it was "interesting how quickly the attitude changed to 'the presidency would be nice, but the House and Senate are more important,'" antitax activist Grover Norquist told Schaller.

"When the house is on fire, you save the baby, not the Van Gogh. And the congressional majorities were our baby"

The House is particularly important because, unlike the Senate, it can be controlled by a narrow majority. "You can run the country out of the House," said Norquist.

"To Democratic ears, the notion that you can govern with the House is patently absurd," Schaller told me. But conservatives whose top priority is to limit government expansion can use their control of the House as a crucial veto point to block new proposals. "Even if you don't have a single senator and you don't have the White House, if you can hold the line in the House you can, quote, 'govern,' if governing means not doing."

This calculus became clear to many in 1996, when Bob Dole's presidential candidacy looked beleaguered and the GOP's newly acquired congressional majorities were at stake. Though conservatives agreed that defeating Clinton would be nice, the prospect of Clinton winning with restored control of Congress was far more terrifying to many conservative activists. "When the house is on fire, you save the baby, not the Van Gogh," Norquist told Schaller. "And the congressional majorities were our baby."

Republicans have learned that it's nice to have the White House but necessary to have the House.

But before getting too carried away here, it's worth remembering Norquist's interests as the head of Americans for Tax Reform. His top priority, for decades, has been preventing new tax increases. And since a president can't raise taxes without Congress, GOP control of one chamber is the best way Norquist can get what he wants.

Conservatives with other priorities, though, will beg to differ that the country can be run from the House. Since the president has such broad leeway to conduct foreign affairs, conservative foreign policy hawks won't get the results they want until the GOP retakes the White House. And social conservatives won't get the Supreme Court appointees they prefer without a Republican president to appoint them. Many businesses would surely prefer a president who'd push less stringent regulations. And the conservative base, of course, will be eager to prevent Hillary Clinton from winning.

Will the GOP's conservatism really hurt its presidential candidate?

Schaller's overriding point is that the ideological positioning of the GOP's congressional wing — so focused on an older, whiter electorate — is dragging down its presidential prospects. But there are at least a few reasons for skepticism here:

After 2014, Republicans' victories in the states are more impressive than ever. It's difficult to assert that their platform has little appeal, or that their congressional wing is hurting their party's overall brand, when they're fresh off such sweeping victories — including in blue states like Maryland and Massachusetts. Yes, this was a low-turnout midterm electorate and not a presidential electorate, but the Republican gains were historic, and they showed that the specter of Republican governance certainly isn't driving angry voters to the polls in off-years. Despite the common belief that Mitt Romney had been forced too far to the right during the primaries, polling actually showed that Americans thought they were closer, ideologically, to Romney than to Barack Obama, according to YouGov polling data reviewed by Lynn Vavreck and John Sides. Fundamentals matter in presidential elections far more than policy platforms. And the past three presidential election results have hewed particularly closely to what we'd expect based on GDP alone, as you can see in this chart (also from Vavreck and Sides):

These latter two points in particular suggest a rather limited role for ideology in a presidential race. While it does seem that a very extreme platform can cause voters to turn against a candidate en masse — look at McGovern's result in 1972, or Goldwater's in 1964 above — the GOP's current platform isn't so radioactive, judging by recent outcomes.

The one caveat here may be the issue of immigration. As Nate Cohn wrote back in 2013, swing state math means Florida is "all but a must-win state for Republicans." Though the state-level GOP is currently thriving there, a presidential nominee who decided to cater to older, whiter voters on immigration might get a different reception.

Floridians Jeb Bush and Marco Rubio, at least, recognize this challenge. But they'll still face difficulty trying to wrangle the competing desires of its conservative and moderate wings, as Dara Lind has written. So will they manage to blaze their own path and create a platform that appeals to Latinos? Or will the harder-line House conservatives prove to be, as Schaller argues, "the tail that wags the dog"?