Sen. Mitch McConnell’s strategy to maintain the Republican majority has been clear: trying to prove that his party can govern. But by saying he will block a Supreme Court nominee who has not even been named, McConnell is headed toward partisan warfare instead.

The death of Justice Antonin Scalia has energized a right flank that has been long suspicious of McConnell and forced him into a fight that is likely to derail his smooth-functioning Senate. The tactic could alienate moderate voters and imperil incumbent Republicans in swing states, but in the supercharged partisanship of a Supreme Court fight, he probably had no choice. By framing his decision as deferring to voters in the next election, people close to him say he has minimized the political risk.

“It was necessary,” said Josh Holmes, McConnell’s former chief of staff, who now works as a Republican consultant. “The suggestion that the American people should have a say here isn’t exactly risky ground to be treading.

“As for the politics,” he continued, “if anyone thinks the center of the electorate is clamoring for Obama to name another left-wing jurist they’re nuts. The liberal left will be as loud as they ever have been, but the reality is that the consternation will be confined to the activist left.”

McConnell’s calculations

McConnell’s other calculation is that if Democrats maintain the White House and take back the Senate, he will at least have denied President Barack Obama a closing victory on the court. If Republicans take over, any heat he will take in the next year for the highly unusual move of blocking a nominee will have been worth it.

He has spent his leadership of the slender Republican majority balancing the demands of conservatives, who view Obama’s presidency as an eight-year constitutional crisis, and his obligations to vulnerable Republicans up for re-election this year. He has chosen the conservatives.

But events in the coming months could confound that decision. Obama’s nominee will put a face on what Democrats will call a clear case of obstruction, giving them someone to rally around. And a divided court must render decisions on abortion-clinic access, affirmative action at universities and Obama’s executive actions on immigration.

Every deadlocked 4-4 decision will spotlight the Senate’s inaction, amplifying Democrats’ cries of irresponsibility but also highlighting the stakes for conservatives set against enabling a left-leaning court majority.

Advance contempt

McConnell’s strategic affront — announcing just hours after Scalia’s death that he would refuse to even consider a replacement — was presaged by other Republican moves over the last two years. A week ago, the Republican chairmen of the House and Senate Budget Committees said the president’s budget director should not be allowed to testify at their budget hearings, a move without modern precedent. Last year, Senate Republicans dragged out the confirmation of Attorney General Loretta Lynch for more than 150 days.

At the heart of nearly every major policy battle between the White House and congressional Republicans has been the contention by conservatives that Obama does not respect the Constitution, almost ensuring advance contempt for any nomination he would make.

“There has been a lot of contention between Republicans and the president on a number of constitutional issues,” Sen. Mike Lee, R-Utah, a member of the Judiciary Committee, said in an interview Sunday. “I think it was really helpful that Sen. McConnell came out and staked out that position when he did. I think he has accurately expressed how the Republican conference feels.”

McConnell, who has spent most of his career steering away from ideological positions, has been known to take fast turns to the right in early stages of a public debate, such as when he endorsed Sen. Rand Paul, his fellow Kentuckian, for president in the incipient stages of his now-suspended campaign. He has also tended to tilt right in debates on the Senate floor on policy issues.

Ted Cruz role central

In a twist, the greatest beneficiary of McConnell’s strategy may be the Republican White House candidate he and his Senate Republicans like the least — Sen. Ted Cruz of Texas, a former Supreme Court clerk whose quick and stalwart opposition to any confirmation is certain to resonate with the most tuned-in Republican primary voters.

Cruz said on ABC’s “This Week” on Sunday that he would filibuster any nominee Obama might offer. “This next election needs to be a referendum on the court,” he said.

At the same time, McConnell’s move makes for uncomfortable times for someone like Sen. Kelly Ayotte, R-N.H., who has a very late primary in a swing state and on Sunday released a statement that said she supported McConnell’s decision. Endorsing McConnell’s strategy could hurt her in the general election, especially if 4-4 decisions on the Supreme Court start piling up.

Sen. Rob Portman, R-Ohio, who is also up for re-election, issued a statement of condolence to Scalia’s family without mentioning the ensuing confirmation fight already engulfing Washington.

Democrats call out McConnell

Democrats were quick to criticize McConnell’s decision.

“McConnell’s precipitous action is reminiscent of his statement in 2010 that his prime goal was to prevent Mr. Obama’s re-election,” said Sen. Chuck Schumer, D-N.Y. “Obama hadn’t presented his proposals for the upcoming Congress; now he hasn’t named a nominee for the court. He realizes it’s better for his senators up for re-election to show he is working in a bipartisan way, but any efforts in that direction have been undone by that action.”

More polarized times

Schumer and other Democrats note that two of the justices on court — Anthony M. Kennedy and Clarence Thomas — were nominated by Republican presidents and confirmed when Democrats held the majority in the Senate.

But these are more polarized times, against the backdrop of an unusual presidential race.

“This is not something that is in debate,” Sen. Bernie Sanders of Vermont, who is seeking the Democratic nomination, said on “Face the Nation” on CBS. “The Constitution of the United States of America provides that the president appoints, nominates a Supreme Court justice. And then the Senate holds hearings and deliberation and votes on whether or not to approve that nomination.”