DENVER (CBS4) – President Barack Obama called it a make-or-break moment for the middle class. The U.S. Senate on Tuesday voted on a bill aimed at closing the pay gap between men and women.

The bill failed but the fallout is far from over. The president and Senate Democrats are tagging Republicans as the party that not only doesn’t care about women’s health, but also women’s pay.

“Ensuring paycheck fairness for women should be a no-brainer and they need to pass that bill,” Obama said.

But the Paycheck Fairness Act never had a chance of passing, and Democrats knew it. They put Republicans on the defensive while courting the female vote on the number one issue facing the country — the economy.

The bill failed on a party line vote and Democrats jumped on GOP nominee Mitt Romney for refusing to support the legislation.

“It’s unfortunate the way the vote came down and the way it’s being used in partisan politics,” Erin Bennett with 9to5 National Association of Working Women said.

Bennett stopped short of saying the issue was being exploited for political gain, but admitted it wasn’t new legislation.

The bill would have required employers to prove wage differences weren’t related to gender. Republicans said it was an unfair burden.

The Obama campaign released a fact sheet including a study that found in Colorado women are paid 79 cents for every $1 men earn. While the gap varies depending on what source is used, it’s safe to say women trail men in overall earnings.

The bill is another indication of just how important the female vote will be this November.

Colorado’s U.S. senators Michael Bennet and Mark Udall were both co-sponsors of the paycheck fairness act.