Why did women do so well in 2012? Because gender bias is declining.

When the 113th Congress convenes in January, women will occupy more seats than ever before. Eighty-one in the House, and 20 in the Senate. Amy Klobuchar better get ready for more traffic jams.

Why did women, most of whom were Democrats, do well in 2012? Observers have offered numerous explanations, including controversial comments about rape and abortion by “self-immolating” Republican candidates, an election-year focus on women’s health issues,redistricting, or a favorable electoral environment for the Democratic Party.

But here’s another: gender bias – either by the media or the voters – is no longer the impediment to female candidates that it once was. That is the conclusion that Jennifer Lawless of American University and I draw in a recent investigation of media coverage of and voter attitudes toward U.S. House candidates. We find that neither news coverage nor voters’ assessments of female candidates reflects the kind of gender stereotyping that has typically pervaded contemporary American politics.