Does it make sense to campaign against anybody in the Senate who endorses Mitt Romney? If Levin's logic was followed half of us would be campaigning for Democrats in the next Senate election, and that would be just plain crazy.
Regardless of what we all think of Ron Paul we need every conservative we can get in the Senate and the House. They may be the only thing holding Obama or Romney back.
No. But it does make sense to campaign against anybody in the Senate who backs Ron Paul -- if he chooses to run 3rd party.