Most of Matthew's commenters took exception to this claim. Spike suggests that women might be turned off by the sexism which is still present even in liberal political communities. He also brings up the "leisure gap," which is the well-documented tendency for men in two-wage households to have more free time. Various estimates put the leisure gap at somewhere between 11 and 19 hours per week. Probably the most famous articulator of the leisure gap is Arlie Hoschchild, who reported in "The Second Shift" that the leisure gap between men and women in two-wage households worked out to an entire extra month of 24-hour days. More recently, a 1995 diary study showed that working men had, on average, 43.6 hours of free time per week - compared to 33 hours for working women. That's a lot more time for blog reading, as Mary from Stone Court, a demographer, also points out in Matthew's comments section.
So women may spend simply spend less time on politics, rather than being less interested. Erika from Apartment 401 points out that young women are more likely to vote than young men [PDF file], and that women are more likely to get involved in influencing others' votes when female candidates are on the ballot. The same link asserts that American women are as likely or more likely than men to participate in non-proselytizing political activity.
While trying to find hard data on women's political participation, I found this fascinating article [PDF file]:
With respect to political development, the knowledge gap is smaller where the democratic history is longer, where there has not been a recent history of authoritarianism, and where civil liberties are higher. The results for women's political context shows an interesting mixture: although, as we might expect, where the national mass culture supports more integrated, egalitarian gender roles, the political knowledge gap is smaller, in countries with more generous parental leave benefits, the knowledge gap is larger. [...]The cross-cultural comparisons suggests to me that the more women have reason to believe that their political opinions are valued, the more involved they are in politics. And that's certainly supported by changes in political involvement as U.S. society becomes more egalitarian: the same article reports that "in the United States in the early 1990s, for example, Burns, Schlozman, Burns, and Verba (1995) found no significant gender differences in voting, protest activity, serving on a local board, or working in a campaign, but they did find gender differences in making campaign contributions, working informally in the community, contacting officials, and political organizational membership," and notes that the gender gap appears to have closed considerably over time.
The longer a country has had experience with electoral democracy, at least for men, the smaller is the impact of gender on political engagement. Similarly, gender differences in political engagement are relatively strong in the democracies recently emerging out of domination by authoritarian communist systems. The
political engagement gap is also relatively small in countries with a gender ideology that is more egalitarian and integrated in its view.
It seems that Matthew is taking women's lesser involvement in a particular kind of political activity - vigorous engagement in political argument - as evidence of lesser interest. Certainly there's more to political participation than rhetoric, although you wouldn't know it from reading a lot of blogs. I put more stock in women's equal involvement in campaign activity, and our greater voting rates. But then again, I'm so vigorous with my rhetoric that people who read my blog have mistaken me for a man - so maybe I'm not the one to ask.