If Powell could enunciate one single Republican position, he would have some credibility.

Since he can’t, conservative Republicans are right in distrusting him.
He can register in any party he wants to, you can’t be “thrown” out of a party, in any case. It’s not the Catholic Church where you can be excommunicated. He is just trying to act the victim.
It would have also been honorable for him to have stepped in during the Plame fiasco and fingered Armitrage, but he didn’t have the decency to do so, it appears.

Someone else can send candygrams to Powell. I’m sure Cheney was just being nice. Painfully nice.