Maybe. But what about Maria Cantwell? Too liberal? I couldn't disagree with her more on most issues, but I was watching her during the Geithner hearings and she really impressed me (superficially, at least).
Cantwell is intelligent, hard-working, driven and isn't afraid to dig into complex policy issues. However, she is a staid, stiff performer on the campaign trail and there have been several reports about her lack of people skills. This would likely derail a Presidential bid, even though she has the intellectual guns to handle the policy side of the job.