TPM Reader TR sees the forest for the trees in Trooper-Gate:

Let’s assume for a minute that Palin, McCain and all of their collective cronies are right about the trooper-gate investigation being 100% a partisan witch hunt, notwithstanding the original vote. So freakin’ what? In the US, congress and state legislatures are tasked with investigating actions of the executive offices. The executives can then present evidence to defend themselves, and their evidence can include displays of outright partisanship if they find it. They cannot legally, however, just ignore the legislative bodies. They are legally required to cooperate. This is theoretically what makes us different from countries like North Korea, Musharraf’s Pakistan, Zimbabwe, etc.

On a second point, how is McCain’s campaign legally able to insert itself into an issue that is solely about Alaska? The investigation has nothing to do with anything outside of Alaska and it predates Palin’s VP candidacy, so it seems to me like some kind of obstruction or interference from a legal point of view.