My position is that the Democrats currently in the Senate are no different than Bernie Sanders. Except that they fear being as honest as Bernie is in his beliefs. Bernie is no worse, no better, than Boxer, Kerry, Kennedy, Hillary...Hillary is a closet Marxist. I wasn't always certain of that, but when she slipped up and repeated the rhetoric about taking from the rich to give to the poor she sealed it. She even had to have a reporter come out with a bogus story about not quoting her correctly. Then the revised quote essentially said the same, only in a verbose way.
The election of a Socialist is a bad thing for the U.S. Senate under any terms, but reality is that we have Socialists in the Senate already. Bernie replacing Jeffords would at most retain the status quo of Socialists represented.
IF Bernie is elected what he will do is become the face of moveon.org. The Face of the Democrat Party. He'll do as Dean did in the primary, draw the Senators further Left. IMO, this benefits the conservatives/Republicans in furthering their majority over the long term. This is why I welcome bernie as a representative for the Democrats IF Vermont must elect a Liberal.
If Republicans can field a conservative Republican, then of course I don't want Bernie elected. But I've yet to see signs they are serious about doing so. They are serious in Maryland, Minnesota, etc..but so far not Vermont. I'd even accept a Liberal Republican IF that Liberal were like Rudy rather than Chafee. Yet I don't see signs of a Rudy Republican yet either. IMO, Reps may give this race a pass to focus on getting Santorum re-elected, picking up more "red" states and challenging vulnerable "blue" seats.