Back in August Matt Stoller first floated the idea of a "Bush Dog" campaign against Democratic members of Congress who enable the right-wing through their support of Bush's policies on core progressive values at key moments.
Now the campaign is in full flight. If you type "Bush Dog Democrat" you now get thousands of results. Profiles of all 38 House Bush Dogs have been completed. Among critics are the DLC, DSCC and insider news source National Jornal.
However it has been primarily focused on House Bush Dogs. However with a little research I found that Senate Bush Dogs are a much bigger problem.