Roll Call has the story:

The Clinton campaign, arguing that the New York Senator is the more electable candidate nationally against the presumptive GOP nominee, Sen. John McCain (Ariz.), pointed out to reporters Friday morning that she has beaten Obama in 16 of 20 House districts that went for President Bush in the 2004 presidential race but are now held by a freshman Democratic Member.

“That is a dramatic difference in how Sen. Clinton runs in these key, battleground districts,” Clinton campaign spokesman Howard Wolfson said at an event sponsored by The Christian Science Monitor. “As a former executive director of the DCCC, I would feel more comfortable with somebody who runs stronger in the kind of competitive districts Democrats will be competing in Congressionally in 2008.”

This contention was bolstered in an open letter to superdelegates that was signed by 16 House Democrats, including freshman Reps. Michael Arcuri, Kirsten Gillibrand and John Hall, all of New York; freshman Rep. Joe Sestak (Pa.); and Reps. Ike Skelton (Mo.) and Debbie Wasserman Schultz (Fla.).

“Hillary has won rural and suburban districts which we as Democrats musts carry to maintain our edge in Congress,” these Members wrote the May 8 letter, which was publicized on Friday.

Sixteen Freshmen Democrats sent a letter to the superdelegates right after the North Carolina and Indiana primaries -- by which time it was pretty apparent that they were campaigning against the eventual nominee. On the one hand, you could argue that by waiting until after those primaries failed to 'change the game,' they risked nothing. On the other hand, why alienate Obama at this point -- unless you really were worried that he would be far worse for your re-election chances than Clinton?

This brings full circle the conventional wisdom on Barack Obama's ability to help down-ballot candidates. In the very districts that are most marginal -- most at risk -- Democrats would rather run with Hillary Clinton heading the ticket than Obama. And don't forget that Democrats have been dreading for years the prospect of running with Clinton.

A lot has changed in the last few months.