Obama cited Census Bureau figures show that the annual earnings of women were 77 percent of what men earned in 2012, a difference that has barely budged over the past decade.
But when measured by hourly earnings, that difference is a narrower 86 percent, according to the federal Bureau of Labor Statistics. The larger gap is in part because women tend to work fewer hours than men and because the annual figures includes items omitted from the hourly data, including tips and bonuses. An analysis of 2012 data by the Pew Research Center placed the discrepancy at 84 cents for women for every $1 made by men.
Underscoring the politics behind the efforts, Democrats were aggressively soliciting campaign contributions, accusing Republicans of standing in the way of pay equity. Democratic Sens. Jeanne Shaheen of New Hampshire and Chris Coons of Delaware, for instance, sent out emails Tuesday drawing attention to the pay gap and directing supporters to a contribution site that was compiling donations for House and Senate Democrats.
Republicans argued that the Senate legislation would hurt women by restricting job flexibility and merit pay.
"The fact is many women seek jobs that provide more flexibility for their families over more money, which is the choice that I made as a young working mom. It is my choice, and I don't understand why Democrats won't respect my choices," Rep. Lynn Jenkins, R-Kan., said.
At a news conference, five male Democratic senators said the issue of equalizing pay for men and women was more than a women's issue.
"Rebuilding the middle class begins with good-paying jobs. And those good-paying jobs won't happen if women are systematically denied fair pay simply based on their gender," said Sen. Jack Reed, D-R.I.
Sen. Chuck Schumer of New York, the Senate's No. 3 Democratic leader, said equalizing pay for men and women was a popular issue and warned Republicans opposing the measure, "We're going to come back to this issue several times this year."