Commenter Steve
expresses the thing that most people bring up when I mention the idea of Janet Napolitano on a national ticket: "She's single, never married, and doesn't seem to have much of a romantic life, so she gets the same closeted-lesbian rumors that dog (fairly or un-) other never-married woman politicians like Condi Rice or Babs Mikulski."
Okay, fair enough. But she was first elected to statewide office in Arizona in 1998. Then she won again in 2002. And then she won again in 2006. So what's the problem, in practice? It's not as if Arizona's a super-liberal state. Bush got a higher proportion of the vote there than he got in Nevada, New Mexico, Colorado, Ohio, Florida, Virginia, Iowa, and Missouri. Compared to, say, Hillary Clinton or Barack Obama there's quite a lot of evidence that Napolitano is a marketable commodity for the median voter.
This article available online at:
http://www.theatlantic.com/politics/archive/2008/01/if-it-plays-in-arizona/47882/