How does one impeach 20-30% of the American electorate? You know the ones I am talking about, the bloodthirsty militarists who think guns and bombs are the answers to most foreign policy problems. Impeaching Bush does no good unless the political power that enabled him is also neutralized. You can't impeach the American militarists.
But let's expand the circle to the next segment of the electorate, the silent partners of the militarists. These are the mild-mannered people who are happy to guzzle the gas and cash the paychecks that come from successful military adventures. When war goes sour, these people complain, but they are really complaining about losing, not about militarism. You can't impeach the militarist exploiters.
Let's not stop there. Let's include the anti-war "cherish our military" crowd. This makes up most of the rest of the population. These folks are eager for peace and don't want to profit from war, but they love our armed forces and want to keep them big, shiny, and well-funded. Maintaining the world's largest adult theme park (US Army, Navy, Air Force, Marines) is bankrupting America, but you can't impeach the military lovers.
So, forget about impeaching Bush, Kossacks; you need to impeach all the war mongers, war profiteers, and military lovers first. Good luck.