You seem to be implying that the tea party groups investigated were not doing so. Care to cite some specific evidence of both?
Michelle Bachmann's own staff is testifying against her about spending irregularities. Sharon Angle (from right here in the great state of Nevada) has already paid $25,000 in fines for spending her campaign funds illegally.
Those are the only 2 Tea Partiers I can name.
I'm a conservative who was once very hopeful that the Tea Party might help turn around the Republican Party (which is more about expanding the government and the debt than anything else). Then I went to a Tea Party rally, where I got to hear all about how it's the duty of all Americans to NOT pay taxes, and how the niggers are taking over.
So yeah, audit them. All of them.