UNITED STATES - JUNE 25: Affordable Care Act supporters hold up signs outside the Supreme Court as they wait for the court’s decision on Obamacare on Thursday, June 25, 2015. (Photo By Bill Clark/CQ Roll Call) Photo: Bill Clark/Roll Call/Getty Images

The pairing of Supreme Court decisions last week, on same-sex marriage and health care, created an impression that the fate of the two issues is joined together in judicial affirmation. “Every once in a while, we bring down the curtain on the politics of a prior era,” the conservative apostate David Frum told the New York Times, “The stage is now cleared for the next generation of issues.” But this is only half-right. The battle against same-sex marriage is lost — conservatives would require a Constitutional amendment to reverse it, a near-unreachable barrier in any circumstances, especially on an issue where public opinion has long since abandoned them.

Health care presents a different story. Conservatives continue to rage against Obamacare, and their capacity to oppose it, unlike their capacity to prevent same-sex marriage, has not fully expired. The strategy of attempting to destroy Obamacare through far-fetched lawsuits has run its course, but Republicans can still have normal political methods at their disposal should they regain power. They have come to focus their energies on the remaining path to obtain this goal, which runs through the final destruction of the Senate filibuster.

If Republicans win the presidential election, their party will control the House, the Senate, and the executive branch. What would stop large chunks of their agenda cold is the Senate filibuster. When the Democratic Party won the trifecta in 2009, they allowed the Senate minority to use the filibuster to impose a 60-vote requirement on all major legislation. The filibuster did not stop Democrats from enacting an aggressive agenda during the first two years of Barack Obama’s presidency, since they were at or near the 60 vote threshold throughout the term, but it did slow their legislative roll.

The filibuster severely hampered Republican ambitions. The party is five seats short of a filibuster-proof super-majority right now, and next year’s Senate elections — held on disproportionately blue-leaning turf — will probably shrink their majority even more. If they want to fulfill their goals, they will have to eliminate the filibuster. That is probably what they’ll do.

Conservative talk radio host Hugh Hewitt is preparing for this possibility by putting candidates on the record regarding their willingness to end the filibuster. Jeb Bush — in keeping with his plan to run his primary campaign like it’s a general election — at first deflected the question, insisting his focus was on developing the long-awaited Republican health-care-reform plan. But when pressed by Hewitt, he conceded, “I would certainly consider that.” Scott Walker — in keeping with his plan to run a primary campaign as though he were sitting atop a throne of his enemies’ skulls — eagerly volunteered, “Yes. Absolutely.” As the Republican primary goes on, conservative activists are likely to extract promises along these lines from all the major candidates.

The filibuster could not stop the entire Republican agenda. Parts of the Republican program could be passed through budget reconciliation, which allows changes to taxes and spending to pass with a majority vote. Republicans could pass big upper-bracket tax cuts, and reductions in Medicaid, food stamps, the Earned Income Tax Credit, housing vouchers, tax credits for health insurance, and other good stuff that forms the core of the Ryan budget.

But important elements of the Republican agenda could not be passed through reconciliation, because they involve regulations, not just taxes and spending. Republicans are very eager to deregulate the financial industry — the promise to do that has helped bring about a massive shift in Wall Street donations from a slight Democratic tilt in 2008 to an overwhelming Republican tilt since 2010. Indeed, the Ryan budget has consistently advocated repealing Dodd-Frank, even though this has nothing to do with the budget at all. It’s a core element of the party’s economic vision.

Republicans could certainly hurt Obamacare by repealing its fiscal elements. Indeed, Senate Republicans reportedly developed a plan to repeal Obamacare that they were prepared to implement if Mitt Romney had won in 2012:

In the months that followed, top GOP Senate aides held regular strategy meetings to plot a path forward. Using the reconciliation process would be complicated and contentious. Senate rules would require Republicans to demonstrate to the parliamentarian that their repeal provisions would affect spending or revenue and Democrats were sure to challenge them every step of the way. So the meetings were small and secret. … By Election Day, Senate Republicans were ready to, as McConnell put it, “take this monstrosity down.”

The trouble with this plan is that only parts of Obamacare can be repealed through budget reconciliation. Obamacare makes health care affordable in two ways. One is old-fashioned cash outlays: The program enrolls people on Medicaid, or gives them tax credits to help afford insurance. The other way is through regulation. The law prohibits insurance companies from charging higher prices to sick customers, or denying coverage for basic medical procedures that only a sicker person might want or need.

If Republicans repeal the fiscal elements of Obamacare while leaving its regulatory elements in place, the health-care market would melt down. Insurers would still be prohibited from screening out sick customers, but healthy people would have no incentive to enroll, since Republicans would have taken away both the carrot (the tax subsidies that make insurance affordable) and the stick (the penalties on going uninsured). Republicans might be willing to melt down the health-insurance markets during Obama’s presidency, but they won’t do it on their own president’s watch. A crippled Obamacare is worse for a Republican administration than a well-functioning version.

And so the only remaining option will be to eliminate the filibuster. The Senate is clearly headed toward this outcome in any case. During the Bush administration, when Democrats began to filibuster judicial nominees they considered ideologically extreme, Republicans threatened to abolish the right to filibuster Court picks. They called such a move the “nuclear option,” a name conveying the sense that its methods — changing the Senate’s rules mid-session — would be so extreme they would permanently alter the landscape. The threat forced Democrats to back down. Under Obama, Senate Republicans began filibustering not only judicial nominations, but also executive branch appointments, as leverage to extract policy changes. When Democrats threatened the nuclear option, Republicans did not back down, and the majority simply changed the rules. Various Washington Establishment figures huffed that the nuclear option would catastrophically impair the functioning of the political system, but no detectable fallout occurred.

These events show that the majority has no reason to allow tradition or procedural niceties to stand in the way of its agenda. If hesitation to change the rules is the barrier standing between a prospective Republican majority and the enactment of its policy goals, then the rules will be changed.

It is possible they would go through some charade to preserve some empty husk of the filibuster. For instance, Republicans might include a total Obamacare repeal in a reconciliation bill, then when the Senate parliamentarian (who determines what can and cannot go into such a bill) objects, overrule that objection via a majority vote. The outcome would be the same no matter what. It would confirm the principle that the majority can actually do whatever it wants.