I think there's a decent shot that Sarbanes might give up his bizarre "I want to be in all media markets" fixation; can't speak to the others. The hardest to ignore will be Steny Hoyer of course.
He doesn't have to campaign; it's a safe seat. What it means is that local news in DC, Baltimore and Annapolis all have to report on him and things that happen related to him because he's a local representative in all three places, so he in theory gets more statewide exposure to set him up for future statewide races.
