WHen Did our Government Become a COVER-nment

Thinking back to the the exposure of the White House coverup of the Watergate break in that led Nixon to resign or face impeachment, I'm forced to wonder now if it is possible to prosecute government officials like Bush, Cheney, Rumsefeld, and so on, who were not forced out of office or appointment (maybe Rumsfeld was at the lsat minute). Nixon went back to California and became a recluse. But Cheney is out there all over the place, with one of his daughters too,defending what he did and denying that it was illegal and calling for the release of CIA documents even though his was the most secretive administration ever. And now we have Senators Lieberman and Graham saying that their law making it illegal to release the still unreleased photos and video of crimes committed at Abu Gharib MUST BE PASSED or they will block ALL legislation even though they have acknowledged that the unreleased materials show even more serious acts of violence and torture than those we have seen and even though Obama has already said, wrongly, that he will not release them. Is this not an open cover up? Isn't it tantamount to legalizing obstruction of justice since Lierman and Graham acknowledge that the evidence shows that (war) crimes were committed?