(CNN) -- An election-year Democratic measure designed to ensure that women don't face pay discrimination was blocked Tuesday by Republicans who complained that the bill was politically inspired and would reward trial lawyers at the expense of employers.
The motion, which needed 60 votes to succeed, got only 52, not one from a Republican.
President Obama issued a statement criticizing Republicans for putting "partisan politics ahead of American women and families."
Senate Majority Leader Harry Reid, D-Nevada, standing at a news conference with pay equity advocate Lilly Ledbetter, accused Republicans of "wanting to stick their heads in the sand" about the longstanding issue of women being paid less than men. "But it's clear where Democrats stand," Reid said.
The bill, which Democrats said would close loopholes in the 1963 Equal Pay Act, would require employers to prove that differences in pay were related to job performance, not gender; would prevent employers from forbidding employees from sharing salary information with each other; and would allow women who believe they were discriminated against to sue for damages.
Democrats acknowledged privately that they expected to make political gains with women by pressing to close the pay gap, which they said has women earning just 77 cents on the dollar compared with men.
Republicans, fearful that Democrats were trying to portray them as insensitive to women, argued that they oppose pay discrimination but disagree with the Democrats' bill, which was written without their input. Republicans remained largely silent about the issue in the days leading up to the vote, even as Democrats, led by the president, made an all-out push for the legislation.
Only one Republican senator, Dean Heller of Nevada, who is in a tight re-election race against Democratic Rep. Shelley Berkley, spoke on the floor against the bill. In his brief speech, Heller proposed an alternative bill to combat the problem, but Democrats criticized it as insufficient.
Off the floor, a few Republicans spoke about the bill, but only when asked by reporters.
"We think it is the wrong way of going about dealing with this issue," said Sen. Mitch McConnell of Kentucky, the minority leader, who described the measure as a reward for pro-Democratic trial lawyers.
"This is just politics. This should be called the trial lawyers bonanza bill," complained Sen. Mike Enzi of Wyoming, the top Republican on the Senate labor committee. "It has nothing to do with the women. They will get very little out of it. What it allows is huge class-action suits with very little defense by any employer."
Even the retiring moderate Republican senator from Maine, Olympia Snowe, whose support Democrats hoped to win, called the Democrats' bill "regrettable" and an "overreach."
"I think there are other ways (of) addressing these issues, and this legislation goes too far," Snow said. The bill "would put a tremendous burden on employers through lawsuits, class-action lawsuits."
Sen. Barbara Mikulski, D-Maryland, the chief sponsor of the pay equity bill, vowed to return to the bill until it passes.
"We will be back," she said. "Though we lost the vote today, we are not giving up for equal pay, for equal rights."