Despite a heavy messaging push from top Democrats, the Senate failed to pass the Paycheck Fairness Act on Wednesday, aimed at cutting into the national gender wage gap -- falling six votes short.

The bill, sponsored by Sen. Barbara Mikulski (D-Md.), had 52 co-sponsors, but Democrats were unable to peresuade any Republicans to vote in favor of the legislation. 

Sixty votes were needed to proceed on the bill, which Democrats vowed they would reintroduce if it failed in Wednesday's vote. The bill amassed 54 votes, before Senate Majority Leader Harry Reid (D-Nev.) changed in his vote to "no" in order to allow him to reintroduce the bill.

Had it passed, the bill would have made it illegal for employers to retaliate against a worker who inquires about or discloses her or his wages or the wages of another employee in a complaint or investigation. It also would make employers liable to civil actions. And as part of this bill, the Equal Employment Opportunity Commission would be required to collect pay information from employers.

Its aim, Democrats have insisted for weeks, is a wage gap that finds women making 77 cents for every dollar that men earn. The push has also been a major plank of the "give America a raise” and "fair shot for everyone" messaging that Democrats hope will mobilize their voter base in this year's midterm elections and help them retain control of the Senate.

Republicans, however, have insisted that while they support equal pay for equal work, the bill would have increased civil lawsuits. They also argue that the bill is unnecessary because discrimination based on gender is already illegal.

Opponents of the bill also pushed back heavily on the White House's repeated claim that women make 77 cents on the dollar compared to men -- which has been called into question by several independent fact-check organizations.