Did they “2” it again? Only if they were Democrats.

As the 113th Congress was sworn in many were pleased about the increased numbers of women in both houses. This was also true for the state legislatures, though not for all of them. While more women are welcome, it’s important to understand that this progress is one-sided, or more accurately, one-partied. In the 2012 election, Democratic women got a big boost. Republican women didn’t.

In January of 2013, women were 29 percent of the Democrats and 9 percent of the Republicans in both houses of Congress. Whereas women increased their presence in the Democratic Caucus from last year, they decreased their presence in the Republican Conference in both numbers and percentages.

After the 2012 election, the number of women Republicans elected to Congress went down twenty percent, from 24 to 20 in the House and from 5 to 4 in the Senate. The number of women Democrats increased by ten and twenty percent respectively, from 53 to 58 in the House and 13 to 16 in the Senate.

Something similar happened in the state legislatures. Republican women decreased their presence by 7 to 8 percent and the Democratic women increased theirs by 3 to 10 percent. As of January, 2013, women are 37 percent of all Democratic state house members and 28 percent of Democratic state senators. They are only 18 and 13 percent, respectively, of their Republican counterparts.

Two factors account for this: Women candidates do well in election years that end in “2.” Women candidates win when the Democrats win. What’s magical about “2” years is that the first legislative contests after the decennial reapportionment are held in those years. New districts create new opportunities. More seats are open — i.e. have no incumbent — in “2” years than in others, and even incumbents must appeal to new constituents within their new district lines.

This has been a factor only since the 1960s when the Supreme Court ruled that legislative districts had to be roughly equal in population. Until . . .

Read more: The Election of Women: 2012