I think a West Virginia special election- even if Joe Manchin runs- could end up being a lot closer than people assume right now. It will depend on whether potentially strong Republican candidates write off their chances if Manchin gets in or decide to make a run at it anyway.
Manchin is one of the most popular Governors in the country we've found in our polling over the last couple years. Another one who falls into category is also a Democrat in a conservative state, Arkansas' Mike Beebe. Back in February, just for the heck of it, we decided to poll Beebe as a hypothetical Senate candidate against GOP nominee John Boozman. We found that despite a stellar 59/22 approval rating, Beebe actually trailed Boozman 44-43 in a hypothetical match up.
That poll showed there is a definite disconnect between how much voters like a moderate to conservative Democratic Governor and how willing they are to send that person to Washington as another vote for Barack Obama and Harry Reid. 50% of McCain voters on that poll said they approved of Beebe's job performance. But only 19% of them said they were willing to support him for the Senate. I would not be surprised if there turns out to be a similar disconnect in Manchin's numbers- the Republicans and conservative leaning independents who like him as Governor may not be willing to support him for Senator if there is a viable GOP alternative.
I certainly still think Manchin is the favorite if there is an election this year and he runs, but I don't know that his candidacy would mean an automatic Democratic hold. We'll poll it if it starts to become more clear that there will be an election this fall.