By a vote of 61 to 36 on Jan. 22, the Senate passed the Lilly Ledbetter Fair Pay Act and sent it to President Obama who plans to sign it into law. The bill will let victims of pay discrimination based on sex, race, religion and other reasons sue employers. Passage came after senators beat back a GOP filibuster against the measure a week before.

The measure had support from civil rights organizations, the labor movement and women’s equality groups. All are key Democratic Party constituencies that saw this bill as a top priority.

All 36 senators opposing the bill were male Republicans. All of the House members who had opposed the bill were Republicans. The House, however, approved the measure as soon as the 111th Congress convened.

Senate Democrats of both sexes voted unanimously for the bill and were joined by the four female Senate Republicans and Sen. Arlen Specter (R-Pa.).

When Obama signs the bill he will overturn a 2007 Supreme Court ruling that said workers — women, minorities or anyone else — who are discriminated against in pay can sue only within the first 180 days after their hire date. The ruling had the effect of barring almost all suits because, on average, most workers discover discrimination well after their first 180 days on the job.

At Ledbetter’s plant, discrimination based on sex was, ironically, not so noticeable because most women workers there did not suffer from wage discrimination. Ledbetter told the World at a teachers union convention she attended last year, that, unlike supervisors such as herself, most of the women working in her plant were covered by their Steelworkers union contract which mandated equal pay for equal work.

Ledbetter, a grandmother from Gadsden, Ala., did not discover that she was the victim of wage discrimination until she had been on the job for 19 years. She sued and won $3.5 million in back pay and damages. Although that award was later reduced in lower courts, the Supreme Court, in a 5-4 ruling, threw her case out entirely. The five justices who voted against her were all men appointed by Republican presidents, including two named by George W. Bush.

So, was the floor fight for passage of this bill a test of how well Senate Democrats will do with their new majority? Quite possibly. The obvious difference is the shift in the balance of forces in the Senate after the Nov. 4 election. With a projected total of 59 senators who will caucus with them, Democrats should be feeling more confident about their power.

Still, without the 60 votes needed to block a filibuster, Democrats and their supporters expressed concerns that the Republicans would use the filibuster to stall progressive legislation. Republicans filibustered a record 94 times in the previous Congress. They blocked bills for a withdrawal timeline for Iraq, funds for veterans, fair pay, the Employee Free Choice Act, renewable energy, health care and education.

On Ledbetter, the Republicans put up a fight. They said people who sue for discrimination often make it up. They tried to weaken the bill with one senator even trying to poison it with a national “right to work” amendment.

Despite three Democratic Senators having missed the vote, the bill passed comfortably.

Don’t get too confident, though. The Ledbetter bill’s companion, the Paycheck Fairness Act, is still pending. It creates stiff penalties for employers who punish workers who talk with one another about their wages and tightens restrictions on how employers can justify unequal pay for equal work.

In addition, Republicans have expressed open hostility, rather than congenial opposition, as is traditional among senators, to the Employee Free Choice Act.

It is quite possible that the Democrats will need all 59 of their votes and one or two defectors from the other party to see these bills pass.

More importantly, the progessive movement will have to raise a stink to make sure the bill stays on the agenda. Labor and its allies have begun a massive public relations campaign on a national and state level to mobilize support, especially in states where Republican senators might feel the heat at reelection time.

Even after the victory on Nov. 4 and the celebration on Jan. 20, it is not time to rest. Struggles for passage of additional working-class legislation should not be left up to the Senate Democrats, alone.

John Wojcik contributed to this article.