The criminalization of politics
When a judge can't be allowed to try a case because of politics, that's the criminalization of politics. The only doubt about his competence is the fact that he participated in the political system. If his participation in Democratic politics makes him unfit, we're heading for apartheid justice systems, one for Democrats and one for Republicans.
And before you get all "he gave money to Democratic groups that don't like Tom DeLay," I'll ask you whether he ever flew on MoveOn.org jet and went duck hunting with the entire organization.
Because otherwise, don't pull that IOKIYAR (It's OK If You're A Republican) nonsense.
If Scalia can claim to be impartial while hearing Cheney's case, Judge Perkins can handle DeLay.