There are secret investigations and secret courts to protect National Security. I think the only way we'll get to hear is when they step down from the Senate. Will they say it's due to family problems? Or will this go as it went for Congressman Cunningham? You know turn about is fair play. Did DOJ put Cunningham out there first as a Republican, before the dems are put out there?
You make an interesting point regarding the secrecy of investigations. This has the potential to be so explosive that there are those who would weigh the cost of the truth as heavily as the weight of the crime. This isn't just about the most recent spying issue, it's the secret prison story, it's Wilson and so on.