I think Byrd has come full circle... though I agree an endorsement would be all the more symbolic.

Byrd and Obama have a close relationship. I had always heard that Byrd was one of Obama's mentors when he arrive in the Senate.

Obama did an important MoveOn.org fund-raiser for Byrd two years ago when Byrd's health kept him from fund-raising on his own. It refilled Byrd's coffers significantly enough to keep any meaningful Republican opposition from jumping in. (Of note, Obama and Clinton both donated $10K directly to Byrd's reelection campaign.)

Obama is also the Dem. Senate leader of the coal-to-liquid fuel caucus. This is an important issue for the West Virginia delegation. (Though not an issue I personally agree with any of them on.) They would have worked closely on that issue, too.

I was quite surprised when Rockefeller, not Byrd, came out first for Obama. I have three theories on this:

1. Byrd is a real "by the rules" kind of guy and may feel that no matter his personal feelings are that he should support what his constiuents decide.

2. Byrd may feel in his role as oldest living Senator and longest serving Congressperson that he should remain a neutral player (like Dean, Pelosi and Reed). FWIW, Byrd is a former Senate majority leader.

3. Byrd may feel that playing an active role in the primaries could hurt Barth's candidacy if she is seen as being, by association, as too closely associated with one or the other of the candidates.

Clinton is running far ahead of Obama in polls here. The past Capito votes that Barth needs to win over are more likely to be Clinton and McCain supporters than Obama supporters.