FWIW, Edwards isn't actually a current senator. He didn't run for reelection in 2004 because he was running for VP.

I'm really happy Dodd is standing up like this, and I want to see Clinton and Obama step up too, but Edwards doesn't really have any action to take here other than condemning the immunity (and keeping pressure on the other candidates about it), which I'm pretty sure but not certain he's done.