WASHINGTON (CNN) -- Senate Republicans blocked a bill Wednesday that would make it easier for people to sue over pay discrimination, an effort to roll back a 2007 Supreme Court ruling that limited such cases.
The Supreme Court ruled unequal pay claims must be filed within 180 days of the first discriminatory paycheck.
Republicans complained that the bill would produce a flood of lawsuits and criticized the chamber's Democratic leaders for putting off the vote until the party's two presidential candidates, Sens. Hillary Clinton and Barack Obama, returned from the campaign trail.
"Here we are, shut down on a Wednesday afternoon, no action in the Senate, in order to accommodate the Democratic candidates for president's schedule," Minority Leader Mitch McConnell of Kentucky said Wednesday.
Though several Republicans joined Democrats in voting to break the filibuster, the 56-42 vote was four short of the needed 60.
McConnell urged senators to block the bill and stick with a debate on a veterans benefits bill pending in the Senate. But Majority Leader Harry Reid of Nevada blamed Republicans for stalling action on that bill to complain about the equal pay bill.
"I have trouble understanding how my friend would have the gall to stand on the floor and make the comment he did, but he did," Reid said. He joined Republicans on the vote, a tactical move that allowed him to request the measure be reconsidered.
The bill, dubbed the Fair Pay Restoration Act, is a response to a 2007 Supreme Court decision that ruled a person who claims pay discrimination must file a complaint within 180 days of that discrimination taking place.
That deadline is specified in Equal Employment Opportunity Commission guidelines, and it "protects employers from the burden of defending claims arising from employment decisions long past," Justice Samuel Alito wrote for the majority in the 5-4 decision.
The bill that stalled Wednesday would have reset the clock with every paycheck, with supporters arguing that each paycheck was a discriminatory act. But Sen. Johnny Isakson, a Georgia Republican, said the bill would allow retirees drawing pensions to sue their old companies over allegations of discrimination that happened decades ago.
"We're about having integrity in the system, so we have timely complaints, we have timely evidence, and the parties that are there can quickly be remedied," Isakson said.
The case was brought by an Alabama woman, Lilly Ledbetter, who claimed that her employer, Goodyear Tire and Rubber Co., paid men doing similar work 15 to 40 percent more. Ledbetter said she discovered the discrepancy late in her career -- too late, the court ruled, to go to court. Watch woman who found out too late she was paid less »
Clinton and Obama spent most of the day in Indiana, one of the two states in the next round of Democratic contests, but both returned to the Senate in time to vote for the bill.
"I'm hoping this chamber will stand up for fundamental fairness for women in the workplace," said Clinton, of New York. "I'm hoping you will stand up and vote to make it clear that women who get up every single day and go to work deserve to be paid equally to their male counterparts."
And Obama, of Illinois, added, "If you work hard and do a good job, you should be rewarded no matter what you look like, where you come from or what gender you are."
Sen. Barbara Mikulski, a Maryland Democrat, called Wednesday's vote "a call to arms" for the women of America.
"We will take it out to the voting booths. We will go on the Internet. We are going to go on TV. We are going to go on the blogs. We're going to tell everybody about this ignominious vote that just occurred," she said. E-mail to a friend
CNN Ted Barrett contributed to this report.