Jay Cost has an excellent response to this tactic:
For the swing voters who determine elections, it's clear by now that the midterm is going to be about the deeply unpopular policies of President Obama. Attacking the Tea Partiers is not going to distract them because the Tea Partiers have had nothing to do with those policies.
Buy they can try it. In fact, go for it. I'm betting it will backfire on them. People are sick and tired of Team Obama blaming everyone else for his missteps. So, go for it.
Vodkapundit has the best quote response to this strategy, and Stacy McCain, the best video.
Meanwhile, I'll be over here ticking off the days until November.