Justice Antonin Scalia’s death hadn’t been public knowledge for more than a few hours before Senate Majority Leader Mitch McConnell issued a statement that will define American politics for months to come. “The American people‎ should have a voice in the selection of their next Supreme Court Justice,” he said. “Therefore, this vacancy should not be filled until we have a new president.”

McConnell’s statement was widely interpreted as an edict, but the text merely conveys a preference. Overlooked at the time, his decision to use the conditional term “should” rather than the declarative term “will” wasn’t an accident. Four days later, it’s clear why he needed to preserve a bit of flexibility. 

As the Republicans’ conference leader, McConnell’s words carry enormous force. But there are already signs that an uncompromising line might not hold. Bloomberg’s Sahil Kapur rounded up evidence that key Republican senators, including Charles Grassley, are already waffling.

“I would wait until the nominee is made before I would make any decisions,” Grassley told reporters in a conference call on Tuesday, according to Radio Iowa. “In other words, take it a step at a time.”

Senator Thom Tillis of North Carolina, who sits on the Judiciary Committee, also sounded skeptical of simply rejecting any nominee at the outset.

“I think we fall into the trap if we just simply say, sight unseen—we fall into the trap of being obstructionists,” Tillis said on The Tyler Cralle Show.

“All we’re trying to say is that based on the president’s actions, it is highly unlikely” he’ll nominate someone in the mold of Scalia, he added. “And if he puts forth someone that we think is in the mold of President Obama’s vision for America then we’ll use every device available to block that nomination.”

As a just-elected, movement-credentialed conservative senator, Tillis isn’t in any real political danger at the moment, but his fellow North Carolinian Richard Burr is up for reelection and highly vulnerable. If Tillis—one of the most conservative Republicans in the Senate—broke ranks within 72 hours in the role of Burr’s human shield, it’s natural to wonder whether McConnell got ahead of himself.

Orin Kerr, a distinguished, libertarian-leaning George Washington University law professor, implies that conservatives should ignore this kind of analysis.

But it’s not just liberal columnists opining. Through their statements, blue-state and purple-state Republican senators like Burr, Wisconsin’s Ron Johnson, and others are communicating concern that an indiscriminate filibuster of President Obama’s nominee will imperil their jobs, and thus the Republican majority.

How could McConnell, whose central purpose for the past decade has been to become majority leader, draft his members into a fight that might knock his party into the minority? Zoom out enough, and you can see the logic.

Start by distinguishing between political and ideological objectives. The ideological argument for foreclosing confirmation at the outset is obvious and incontestable. If Obama’s nominee is confirmed, Scalia’s seat—and along with it the ideological bearing of the full Court—will fall into liberal hands. Waiting Obama out keeps hope alive for conservatives that a Republican will win the presidency and restore the prior balance. In a political vacuum, the impulse to fight rather than surrender makes perfect sense.

Even outside a political vacuum, McConnell’s red(dish) line makes some sense. In the near-term, by telegraphing his intention to deny Obama’s nominee a fair hearing, he shields vulnerable members from pressure to compromise, and thus from the threat of right-wing primary challenges.

But beyond the near term, this political logic collapses. If the line does hold, McConnell will have effectively nationalized these same Senate races—races Republicans need to win to preserve their majority—and provoked a turnout-driven crisis in a presidential election. Republicans have an existential interest in keeping turnout low, but Democrats will use the Senate’s obstinacy and the threat of another arch-conservative justice to bring out voters in November. And if Republicans lose the presidency, of course, they don’t just lose Scalia’s seat, but possibly one or two more.

It is absolutely within the Republican Party’s power to deny Obama another Supreme Court appointment. Unlike other conservative objectives (defunding Obamacare, deporting more Dreamers), it doesn’t require threatening to shut down the government. But just like keeping the government shuttered, maintaining a Supreme Court vacancy for eleven months is a matter of will. And the politics are likely to resemble a slow-burning shutdown.

From this vantage point, McConnell’s Saturday statement starts to look like a tremendous error. But it’s only an error if you assume his sole political obligation is to his party as an institution—to preserve the GOP’s Senate majority, and to strengthen his party’s hand in the presidential election. That’s self-evidently not the case. McConnell has a similarly potent interest in being reelected Senate Republican leader. And his priorities—strengthening the party, being reelected leader—are actually competing here.

Slow-walking a nominee to confirmation would pose the smallest risk to McConnell’s majority, but the greatest risk to his leadership. Movement conservatives would insist he be deposed. He could save the Republican majority, but make it extremely difficult for members of that majority to make him their leader. 

Even if McConnell ends up caving—he has signaled in the past that resistance will be extremely difficult—his seemingly reflexive overreach makes a great deal of sense as an opening bid. His weekend statement was resolute enough to establish a preference, but elastic enough to abandon it if necessary. And that means he’s given himself wide berth to balance his institutional duties and his instinct for self-preservation.