Democrats and the White House put on a coordinated full court press today, calling on Republicans in the senate to support a bill called the "Paycheck Fairness Act," which is billed as an effort to help achieve income parity for women.

The senate is scheduled to hold a procedural cloture vote on the bill Tuesday even though it is not expected to get the 60 votes needed to move forward in the senate without Republican support.

Democrats describe the paycheck fairness bill as "the next step" bringing the Lilly Ledbetter Fair Pay Act - the first thing President Obama signed into law in 2009. This new bill is meant to bring that law up to date by finalizing and closing loopholes that some say that still exist that keep women earning less than men for the same work.

"American women are mad as hell," Sen. Barbara Mikulski, D- MD., sponsor of the bill said today on a conference call, noting that women still make 77 cents for every dollar that men make for the same job requiring same set of education. That data comes from a study of 2010 government statistics by  group called the Institute for Women's Policy Research.

The bill will most certainly become a flashpoint for talking points, campaign ads, and election-year messaging which may be part of the Democratic calculus for moving toward the bill now as a narrative in the so-called " war on women," narrative. Democrats today wasted no time to frame tomorrow's vote in the context of presidential politics, challenging Gov. Mitt Romney to support the measure.

"We urge him to speak out and endorse this legislation ahead of the Senate vote," Sen. Chuck Schumer. D-NY., said of Romney, "Today he has refused to take a position on this important proposal. Well the silence is hurting our chances of advancing this legislation in the Senate. Because if he, as the standard-bearer of his party were to endorse this legislation, it would almost certainly cause the Republicans in the Senate to follow his lead and join Democrats to endorse this key reform."

Discrimination on the basis of sex is already against the law.  But the Paycheck Fairness Act would require employers to demonstrate that wage gaps between men and women doing the same work have a business justification and are truly a result of factors other than gender.   The bill would prohibit employers from retaliating against employees who share salary information with their co-workers.

The bill would create federal grants to improve women's salary negotiation skills and changes parts of the  Equal Pay Act of 1963 to protect women who take initial steps in filing an unfair pay complaint. It would give workers stronger tools to combat wage discrimination, and help ensure more adequate compensation for gender-based pay discrimination, Democrats say.

Republicans are apprehensive about the bill because they believe that the Civil Rights Act of 1964 and the Equal Pay Act of 1963 already have broad coverage over paycheck fairness.

They believe the proposed Paycheck Fairness Act would allow the government to "second-guess" employee wages and encourage lawsuits. They also point out that the bill would violate employee privacy by allowing employees to reveal their colleagues wages or salaries and that that the bill could also eliminate employee pay incentive programs, because such programs, by design, pay some workers more than others.

Senate Majority Leader Harry Reid, D-NV., said if Republicans vote against the bill tomorrow they'll be "sending the message to little girls across the country that their work is less valuable because they happened to be born female."

President Obama today also placed himself in the middle of this issue, telling supporters on a conference call that it is an  issue of "fairness."

"If Congress doesn't act then women will still have difficulty enforcing and pressing for this basic principle," he said.

If this bill hits a roadblock in Congress, which it will likely tomorrow, the White House has not said yet if President Obama will sign an Executive Order to go around Congress.

"All our efforts right now are devoted to getting this act passed," Senior Adviser to the President Valerie Jarrett said on the conference call with Senate Democrats today, "There's no interest right now in talking about a fallback."