You're right that, at this point especially, the MSM would portray Bush as "flailing wildly," etc., if he dared to trash the Rats. One reason why he should have attacked the Rats all along in this administration, once they started going viciously after him. In politics, if you suddenly start doing something you haven't been doing before, it looks like you're either desperate or cynically pandering.
Well, Bush and his PR team might try fighting back against the liberals for once. They could actually win for once.