US DoJ says that highly-ranked White House personnel are exempt from subpoena.
The Department of Justice snuck back home with its tail between its legs earlier this month after deciding that senior White House officials are exempt from subpoena and thus can freely ignore summons to testify. That's right... they don't have to show up in court if they don't want to, especially with regard to questioning about the possibly illegal firing of eight US prosecuting attorneys. The House Judiciary Committee has been trying to get to the bottom of this because, in the past couple of years a number of prosecutors that didn't toe the party line exactly lost their jobs, and to that end they've been trying to get people who were closest to the matter on the stand. Over and over again, those summoned are saying that they will not appear, that they will not testify, and that they've got the backing of George W. Bush telling them that they are immune from any such legal compulsion. Now the question is whether or not they can be brought up on charges of contempt of court for their actions, but if they can't even be commanded to show up in court there is a snowball's chance in a blast furnace of that ever happening. The few who have set foot before the committee, such as Sara Taylor (former unspecified White House official), gave only partial information, usually to save their own asses, and cited privileged protection as their justification for avoiding any other questions.
Technically, however, this is how privileged judicial protection is supposed to work: You have to appear in court and give at least some testimony, but you can refuse to answer certain questions, or at least that's how professor Stephen Gillers of NYU's law school put it.
I don't think that I'm going out on a limb by saying that nothing is ever going to come of this. The people in power in this country right now have a master plan and they're following it to the letter. They've also got the rest of the government that they could conceivably have to answer to for their actions set up in such a way that their hands are tied and what options they have are limited. In a month or so this whole thing will be forgotten about by the media, and the people around the same time.