WASHINGTON — Senate Democrats deflected an initiative by Republicans on Saturday that would have forced U.S. and Russian negotiators to reopen an arms treaty reducing stockpiles of nuclear warheads.
But the 59-37 vote against an amendment by Sen. John McCain, R-Ariz., indicated the difficulty President Barack Obama is having in trying to win Senate ratification of the treaty before a new, more Republican Congress assumes power in January.
Treaties require a two-thirds majority of those voting in the Senate, or 67 votes if all 100 senators vote.
Florida Democratic Sen. Bill Nelson voted with the majority; Republican Sen. George LeMieux voted with the Republican minority.
Led by McCain, Obama's GOP opponent in the 2008 presidential election, Republicans tried to strike words from the treaty's preamble that they say would allow Russia to withdraw from the pact if the United States develops a missile defense system in Europe.
The treaty is a foreign policy priority for Obama, who signed it in April with Russian President Dmitry Medvedev.
It would limit each country's strategic nuclear warheads to 1,550, down from the current ceiling of 2,200, and establish a system for monitoring and verification. U.S. weapons inspections ended a year ago with the expiration of the 1991 arms control treaty.
Obama used his weekly radio and Internet address Saturday to call for ratification.
He also tried to allay GOP doubts with a letter Saturday to Senate Minority Leader Mitch McConnell, R-Ky., pledging to carry through with planned U.S. missile defense facilities in Romania and Poland that would be capable of intercepting a missile from Iran aimed at the United States.
The treaty has received the backing of current and former military and national security officials, as well as former Republican President George H.W. Bush.
Democrats said a reference in the treaty's preamble on missile defense systems is nonbinding and has no legal authority. In his letter, Obama said the United States disagrees with Russian statements about the threat that a missile defense poses to the strategic balance between the two countries.