If you read a lot of progressive blogs, you probably already know about this, since it was trumpeted last night as perhaps a bigger deal than the presidential primaries, but in any event: Donna Edwards decisively beat incumbent Democratic congressman Albert Wynn in a surburban DC district of Maryland.

Edwards came very close to upsetting Wynn two years ago. Her candidacy this time around probably drew more national attention and support from progressive netroots circles than any since the Lamont challenge to Joe Lieberman.

Wynn got the bullseye painted on his back for a variety of reasons, most notably his reliance on corporate contributions, and particularly his vote for bankruptcy "reform" legislation, a longstanding progressive cause celebre that's gained new life thanks to the mortgage foreclosure crisis, which hit Wynn's district disproportionately. This district, probably the wealthiest majority-African-American CD in the country, is centered in Prince George's County, with a slice of Montgomery County as well.

There was some talk as recently as yesterday that Wynn might pull a Lieberman and run as an independent in the general election if he lost the primary. But he's already endorsed Edwards, and this is a heavily Democratic district.

This primary will be treated as another object lesson in the willingness of progressives to "primary" wayward Dems, and also as part of a longer-range struggle within the African-American political community wherein membership in the Congressional Black Caucus no longer ensures perpetual re-election.