Washington ? Republicans went to the Supreme Court Thursday to try to stop New Jersey Democrats from replacing Sen. Robert Torricelli on the Nov. 5 ballot for a re-election race he seemed likely to lose. Control of the Senate could hang on the court’s reply.

The Republicans want the justices to block a unanimous ruling from New Jersey’s highest court that would let former Sen. Frank Lautenberg jump in for Torricelli, whose ethics problems had become the focus of the race after he was admonished by the Senate.

Less than two years after the Bush v. Gore case settled the 2000 presidential fight, the Supreme Court was once again in the middle of a high-stakes fight over state election rules.

There was no immediate word whether the justices would block the lower court ruling or agree to hear the Republicans’ broader constitutional complaints. The court asked the New Jersey Democratic Party to respond in writing to the GOP’s legal filing.

Republicans argue it’s too close to Election Day to replace Torricelli and that the Democrats should not be allowed to dump a candidate just because he’s trailing.

“If the lower court ruling is allowed to stand, political parties will be encouraged to withdraw losing candidates on the eve of election, replacing them with candidates who have not gone through the rigors of the nomination process in hopes of snatching victory from the jaws of defeat,” the GOP filing said.

New Jersey law bars replacement of candidates less than 51 days before an election, the GOP said. The lower court ruling would switch the candidates 33 days before Election Day, the party said.

Democrats control the Senate by one seat, so the New Jersey race could be key in the Nov. 5 elections. Democrats chose Lautenberg, 78, as Torricelli’s replacement on Tuesday and he was campaigning hard on Thursday, saying, “I realized how much I missed it.”

New Jersey senatorial candidate Douglas Forrester and the state's Republican Party are challenging the candidacy of former Sen. Frank Lautenberg, a late replacement on the Nov. 5 ballot. Above, Forrester enjoyed an ice cream cone while campaigning Thursday in Princeton, N.J.

Lautenberg, who retired from the Senate in 2001 after three terms, greeted commuters at a rail station in Hoboken, N.J., then traveled to Washington to meet with Senate Majority Leader Tom Daschle and with national labor leaders.

The 2000 presidential election fight in Florida set a precedent for the Supreme Court to get involved in state election fights, the GOP argued.

The high court heard two election-related cases after the too-close-to-call voting that year. The decisive Bush v. Gore case ended ballot recounts in Florida sought by Democrat Al Gore and effectively called the election for George W. Bush.

Richard Hasen, an election law professor at Loyola Law School, said the court had far less reason to get involved this time around.

“It may well end with a fizzle instead of a bang like last time,” Hasen said.