It wasn't bad. In fact it was pretty good in some ways and the annoying bits weren't too hard to ignore.
The end was sort of bad. Not the choices that I'd make. It took conspiracy a bit too far, away from conspiracy to "this is the way the world works." It *should* have been enough to expose the Senator and his fellows. Where was the press in this?
The idea wasn't too bad. The speech his spotter's widow gave about her dead husband's choices was good. (Though why she'd go back to using her maiden name I can't imagine.) Among all those willing to look the other way were several people who were... righteous.
But overall it wasn't a "conspiracy" movie. There wasn't a "conspiracy" there was only finding out the "truth" of reality. In this world president Bush really could have blown up the world trade center buildings, the pentagon, and disappeared four aircraft full of people. It made me wonder if the writers and producers are Truthers. They even (cleverly) tied the story into real world events to support the story-reality by mentioning WMD and Abu Ghraib.
Why does Hollywood do this? Why does it give us movies that will appeal to people who like "special forces soldier as hero" movies and who want to see Truth, Justice, and Heroism win out over evil, and then put in this nihilistic sub-text and Truther reality?
Because it's just going to piss off the audience. The result is a movie that appeals to neither group of people. And it tanks.