Is Pol. Success Easier for Single Women?

I found this article in today's Washington Post interesting...

The Bush administration, it appears, is suffering from a serious but little-noted problem: a "marriage gap." That is, a top female official is almost five times as likely to be single as her male counterpart.

In a fact-filled survey of 367 top administration officials by the National Journal, 33 percent of the women, but only 7 percent of men, were single. This may suggest that, to get ahead, it's better for women to be single.

Any thoughts on this???