Most Republican senators facing tough re-election races support Majority Leader Mitch McConnell’s call to hold off on confirming a Supreme Court nominee until after the presidential election.

Justice Antonin Scalia’s death Saturday sparked praise for his work on the court and calls from Republican leaders and presidential candidates alike to let the next leader of the free world replace him.

The issue is taking center stage in the fight to control the Senate, led by McConnell, who is determined to keep his 54-46 majority.

“The American people should have a voice in the selection of their next Supreme Court Justice,” the Kentucky lawmaker said in a statement Saturday. “Therefore, this vacancy should not be filled until we have a new president.”

While Democrats immediately cried foul, Republicans senators facing difficult re-election campaigns generally agreed with McConnell.

Rob Portman of Ohio, Kelly Ayotte of New Hampshire, Ron Johnson of Wisconsin and Pat Toomey of Pennsylvania – all representing states President Obama won in 2012 and among the incumbents most-targeted by Democrats – said the nomination should wait until 2017.

Republicans backing McConnell’s decision may have calculated that opposition to Obama and his potential nominee will excite their base more than it will motivate their Democratic opponents, and that the issue of a Supreme Court seat will not necessarily be the biggest fault line in the election come November.

“I believe the best thing for the country is to trust the American people to weigh in on who should make a lifetime appointment that could reshape the Supreme Court for generations,” Portman said in a statement Monday.

But Democrats quickly jumped on that stance. Both of Portman’s potential opponents in the race – former Ohio Gov. Ted Strickland and Cincinnati City Councilman P.G. Sittenfeld – criticized him for the decision. Strickland said Portman “abandoned his constitutional duties” by arguing to hold off on a nomination, and that he is “shirking his responsibilities to our nation.”

In New Hampshire, the arguments were much the same: Incumbent Ayotte – who faces a challenge from Gov. Maggie Hassan – said that the American public deserved the opportunity to weigh in on which party should be able to fill the vacancy. Hassan called holding off is an “abdication of the Senate’s constitutional duty.”

Toomey conceded that Obama has the constitutional authority to nominate someone for the court – something the president has already said he will do in the coming weeks – but said regardless of whom that person is, “his nominee will be rejected by the Senate.”

Johnson, who is facing a rematch of the 2010 Wisconsin election against former Sen. Russ Feingold, agreed that the nomination process should wait until next year.

The fifth Republican seen as a major target for Democrats, Illinois Sen. Mark Kirk, didn’t take a position on the issue. Instead, he praised Scalia as a “giant in the history of American jurisprudence” and labeled the political debate “unseemly. Let us take the time to honor his life before the inevitable debate erupts.”

One of Kirk’s potential challengers, Rep. Tammy Duckworth, however, quickly criticized him for declining to take a position.

“Senator Mark Kirk must immediately level with the people of Illinois, and let us know whether he supports the Constitution, or if he’ll be a rubber stamp for Mitch McConnell’s obstructionist and unconstitutional gambit,” Duckworth said in a statement.

Who fills Scalia’s seat is likely to be one of the major issues in November’s election. The late jurist was a consistent conservative voice on the court, and the appointment – and confirmation — of a liberal justice would swing the majority to the left ideologically, a shift that could last for decades if a Democrat wins the presidential race. If the Senate doesn’t confirm a new justice, the court may see many 4-4 decisions for the remainder of this year.

While McConnell has argued that the Republican majority was extremely productive in 2015, there are few pieces of business expected to make it through the upper chamber during this election year. And since McConnell immediately stated his opposition regarding this major Senate task, it could create an opening for Democrats eager to paint the majority party as obstructionist.

And the politics will also depend on the pick — if Obama nominates an African- American, Hispanic, Asian-American, or a woman, any GOP delay on confirmation hearings could rally the Democratic base. The president also could nominate a senator – Democrat Amy Klobuchar and Republican Orrin Hatch have been mentioned – prompting questions as to whether the chamber would hold up the confirmation of one of its own.

The first step in the process, however, would involve the Senate Judiciary Committee, and none of the Republicans facing difficult re-election races sit on that panel. If the committee were to take up the confirmation process but not approve a nominee, it would prevent a floor vote and blunt some of the attacks from Democratic challengers to the imperiled GOP incumbents.

Before the nomination process could even take off, however, Democrats leapt at the opportunity to both criticize Republicans’ for arguing that the nomination should wait, and to fundraise off that criticism.

Senate Majority PAC, a Democratic outside-spending group, sent a fundraising email Monday afternoon accusing McConnell of taking the Supreme Court “hostage.”

Duckworth’s campaign also sent an email asking supporters to sign a position calling on Kirk to state his position on the issue, while Hassan’s campaign blasted out a petition calling for Ayotte to change hers. Katie McGinty, one of three Democrats in Pennsylvania running in the primary to face Toomey, also circulated a petition on the matter, and issued a call for donations to her campaign.