Reply #1: I bet at least one of these three is true:

[UrbScotty]

1. You will vote for him again, since his seat isn't up until 2014 and you will have forgotten this vote by then.
OR
2. You're demonstrating a lack of perspective by making this one vote seem much more important than his entire record of progressivism through the decades.
OR
3. He won't even run again in 2014, since he'll be 80.

Nobody in Congress is perfect. Not Levin, not Stabenow, not Kucinich, not Feingold, not Sanders. But if enough people actually refused to vote for Democrats based on one single vote, progressive Democrats would keep losing time and time again.