Self-preservation is what many think was the reason he failed to arrest her in the first place. regardless, new evidence has emerged and if he did not act on it he would be defacto  "covering up". He told congress and the American people there was no case, he is required to tell them that there now is.

But I understand your not liking it. Had such a thing happened to my preferred candidate I would be suspicious also, I guess it's lucky for me that I don't have a dog in this race.