The Hobby Lobby case will dominate the news when the decision is released later today, and there’s something important to watch out for if, as expected, the Supreme Court’s conservative majority rules against the Obama administration. If Republicans react to the decision by framing it as about restraining President Obama’s power as much as about corporate religious freedom — if you hear a lot of words like “overreach” and “lawlessness” and even “tyranny” in their comments — then it will be clear that Republicans are coalescing around a strategy that could frame their opposition all the way to January 2017.

Whether House Speaker John Boehner timed the announcement of his lawsuit against the president to coincide with last week’s Supreme Court decision on recess appointments (it did seem a bit rushed, since Boehner didn’t seem to have time to assemble a list of particular complaints), this is now a centerpiece of Republican rhetoric. The idea that Obama is a tyrant wiping his muddy boots on the Constitution as he goes about his project to destroy the United States used to be the province of spittle-flecked talk radio hosts, right-wing Web sites and those chain e-mails your father-in-law reads while he watches “Hannity.” But it has now moved to the core of the GOP’s case against the president. As Karl Rove said on Fox News Sunday yesterday, “This is imperial power. This is George III. This is some monarch to say I am the law.”

Republicans will say that it’s because Obama has grown increasingly lawless and tyrannical. And it’s true that he is moving from urging Republicans to pass legislation (a pointless exercise if ever there was one) to finding ways he can take executive action and making the case for those moves, some of which have a greater impact than others. For instance, Congress won’t raise the minimum wage, so Obama used his authority over federal contracting to require companies that get government contracts to raise their minimum wage. That’s good for the people who work for those companies, but it’s a relatively small portion of the nation’s workforce. The coming Environmental Protection Agency regulations on carbon emissions from power plants, on the other hand, tackle the single largest source of greenhouse-gas emissions, so a regulatory action can have a more significant effect on the larger problem.

But there’s another reason that Republicans are focusing so intently on the idea that Obama is a tyrant: Their last overarching critique about this administration, that it is scandal-tainted and fundamentally corrupt, hasn’t been able to cross over into the mainstream. Every time they think they’ve caught the administration in something that will lead to Obama’s impeachment, the investigation turns up less than they’d hoped for. Obama wasn’t brought down by Solyndra, or Fast and Furious, or the IRS (though they’re still trying on that one), or even by Benghazi.

Although the GOP base knows in its heart that Obama is corrupt, Republicans haven’t been able to convince the country of that. So the idea that he’s a tyrant offers a new opportunity to put every particular objection into a larger framework. Because the argument is about process and not substance, they can make the claim even on issues where they’re on the wrong side of public opinion, like the minimum wage or climate change. And it allows them to feed their base’s anger, convincing tea partyers that they’re all focused on the same thing.

For the moment, we can leave aside the question of whether Obama is, in fact, a tyrant (there will be plenty of time to assess that in detail). But what’s becoming clear is that this idea, which used to circulate mostly on the conservative fringes, is taking a central place in Republican rhetoric and strategy. They might not stop talking about it until the next president gets sworn in.