Of the 435 members of the House of Representatives, 65 are women - far more than were there five decades ago but obviously far fewer than their numbers in the population. In their new volume, "Breaking the Political Glass Ceiling: Women and Congressional Elections," two political scientists come up with some genuinely surprising explanations - and a radical idea for accelerating a change.
Barbara Palmer of American University and Dennis Simon of Southern Methodist University have looked at every race with a woman candidate from 1956 through 2004, searching for the characteristics of the places where women won - and why.
One finding was predictable. The single biggest barrier to success was simply the fact that most incumbents are men - and almost all incumbents win. The success rate of women running against incumbents is minuscule. In 10,866 House elections during this period, they found only 13 female Democrats and eight women Republicans who defeated incumbents.
But beyond that, it turns out that there are specific characteristics for districts that are friendly or hostile to women candidates - at least as far as white women are concerned. The scholars could find no significant differences in terms of geography or social characteristics between those districts that elected African-American men and African-American women. Almost without exception, they were heavily Democratic, urban and working class.
But the picture is very different for white women candidates. "Female Democratic House members tend to win election in districts that are more liberal, more urban, more diverse, more educated and much wealthier than those won by male Democratic members of the House," they write. "They come from much more compact, 'tonier,' upscale districts than their male counterparts."
The map that they showed me and is available on their Web site (www.smu.edu/politicsandwomen.com) depicts the clustering of those districts in California, the Northeast corridor and urban areas from Cleveland and Detroit through Chicago, St. Louis, Denver to Portland and Seattle.
The home base of Minority Leader Nancy Pelosi typifies the kind of district that elects a Democratic woman. Her San Francisco district is tiny in area, 100 percent urban, highly diverse (majority-minority, in fact), well above average in income and education, more white collar than blue collar - and overwhelmingly Democratic in presidential preference and liberal in ideology.
Democratic women do better in those areas than in the older, ethnic, blue-collar, labor districts that were the backbone of the New Deal. Where older values and customs and gender stereotypes prevail - as in much of the South - women candidates have a harder time.
The picture is different in some respects for Republican women. Because women candidates of both parties are perceived by voters as more liberal and socially sensitive than men, "female Republican House members tend to win election in districts that are less conservative, more urban and more diverse than those electing male Republicans; they come from districts that are less Republican," and therefore more competitive.
That is why Republican women such as Anne Northup of Louisville and Heather Wilson of Albuquerque are always on the Democrats' target lists. In general, the authors find, districts that nominate Republican women are similar in their makeup to districts where Democratic men can win. That is another reason the House has more Democratic women than Republicans.
Partisan preferences aside, there are many similarities between districts that elect Democratic and Republican women. Those districts rank above average in income, college graduates, ethnic and racial diversity and they tend to be more urban. They are lower than average in their Republican presidential vote, their size, their school-age population and their percentage of blue-collar workers.
Combining those characteristics, Palmer and Simon develop a scale measuring how "woman-friendly" each district is. It turns out that Pelosi represents the most "woman-friendly" district in the country. Three other California districts and three in New York, also held by Democratic women, are among the 18 most "woman-friendly" districts in the country, along with one outside Chicago.
But 10 others of the 18 are now held by male Democrats: Reps. Mike Capuano of Massachusetts, Rahm Emanuel of Illinois, Chris Van Hollen of Maryland, Bill Pascrell of New Jersey, Jim Moran of Virginia, New Yorkers Gary Ackerman, Jerrold Nadler and Eliot Engel, and Californians Tom Lantos and Mike Honda. If those seats turn over, women have a good chance of winning.
Demographic changes now under way will increase the number of districts where women can compete. But the radical suggestion from Palmer and Simon is for states to use this knowledge of what makes a district "woman-friendly" in the next round of redistricting, after the 2010 Census, to increase substantially the number of women in Congress. As women in state legislatures position themselves for the coming redistricting battles, that's something they can keep in mind.
- David Broder is a columnist for Washington Post Writers Group.