Female Democrats are the most effective progressive force in American politics, according to a new study. Emily’s List, an organization that supports and funds pro-choice Democratic women for elected office, produced a new study showing that when women are elected, they vote more on progressive women’s issues than other Democrats.

The study was based on National Journal rankings of elected officials. Emily’s List found that Democratic women have been the most liberal members of Congress over the past 23 years.

“We also found that Democratic women have been the most liberal members of the Senate for 20 of the past 23 years, with a voting record that is 3.3 points more liberal than that of Democratic men,” the organization determined. And in the House, Emily's list reports that Democratic women are more than "8 points more liberal than Democratic men overall, and nearly 10 points more liberal on social issues." Overall, the Emily's list study found that "when all 535 Members of Congress were studied, Democratic women were consistently more progressive than their colleagues. The same was true on social issues.”

Emily's List's methodology for the study:

"National Journal vote ratings were used to measure how Democratic women in office, over a twenty-two year period, have voted on liberal and social issues. Each year, National Journal publishes vote ratings on current members of Congress. Members are rated on a series of votes, chosen by National Journal. The votes are categorized into liberal social, liberal economic, liberal foreign policy, conservative social, conservative economy, and conservative foreign policy. Then, each member is given a liberal composite and a conservative composite score. We measured the liberal social and liberal composite scores of Democratic women, Democratic men, Republican women, Republican men and all of members of Congress. "

Emily's List has supported a number of prominent elected very progressive Democrats in recent years. The group endorsed Senator Elizabeth Warren in the 2012 elections, and have endorsed a number of women candidates for House and Senate for next year's elections.