Bush is the lynchpin. Attacking him destablizes the whole system. He has the ability to pardon criminals and appoint more cronies and make the problem worse overall. He is like the running faucet that we have to turn off before we can mop up the rest of the mess. It's not just Congress! There are many, many "insiders" who are not elected officials who are solely appointed by the president.

Also I am certain there are a lot of people who support the administration who believe that homosexuals and muslims aren't human. Denying civil rights is the first step along the path to denying humanity.