By Susan Cornwell and Eric Beech
WASHINGTON (Reuters) - Republican Senator Mark Kirk, facing a tough re-election fight in Illinois, said on Monday the Senate should vote on whomever President Barack Obama nominates to the U.S. Supreme Court, breaking with his party's leadership.
A heated political fight has erupted over filling the court's vacancy left by the Feb. 13 death of conservative Justice Antonin Scalia, with many top Republicans threatening to block any nominee put forth by the Democratic president.
Senate Majority Leader Mitch McConnell has said the seat should remain vacant until Obama's successor takes office in January so voters can have a say on the selection when they cast ballots in the Nov. 8 presidential election.
Kirk wrote in an opinion piece in the Chicago Sun-Times that he recognizes the right of any president to choose a Supreme Court nominee and he looks forward to Obama picking one for the Senate to consider for confirmation.
"I also recognize my duty as a senator to either vote in support or opposition to that nominee following a fair and thorough hearing along with a complete and transparent release of all requested information," Kirk added.
Kirk, who holds Obama's former seat in the U.S. Senate, said he hoped the president would pick a nominee "who can bridge differences, a nominee who finds common ground and a nominee who does not speak or act in the extreme."
Obama's nominee could shift the court to the left for the first time in decades.
Kirk's stance illustrates that McConnell may have trouble keeping Senate Republicans fully united over filling Scalia's seat. Some senators like Kirk may find themselves in a tricky situation as they seek re-election this year in states where Democrats are competitive, as they are in Illinois.
But it appeared unlikely that enough Republicans would peel away from McConnell to allow a vote on the Senate floor.
Republican Senator Orrin Hatch of Utah said on Monday it was up to McConnell and Judiciary Committee Chairman Chuck Grassley to decide whether to hold confirmation hearings. Hatch is a member of the committee and its former chairman.
"I feel like we ought to put it off and get it out of this harsh atmosphere," Hatch told reporters. "... I think to get it in the middle of this intense political season is not the best thing to do."
Jeff Flake of Arizona, another Judiciary Committee member, on Monday backed McConnell's stance.
(Reporting by Eric Beech, Susan Cornwell and Richard Cowan; Writing by Will Dunham; Editing by Eric Walsh and Howard Goller)