By impeachment we generally mean the entire process which entails the subsequent vote on removing the official and conviction. If Bush was removed, we certainly would save lives (that is, if Cheney were convicted too).

And you most likely do have a point on it not happening. Likely the Democrats would get the vote on impeachment in the House but he would probably get acquitted by the Senate, like Clinton. But I think that the case of convicting Bush is very high; probably higher than any other prior President including Nixon. I think if irrefutable evidence is presented, then if the Senate doesn't convict him then he will probably get indicted by a federal grand jury. Just because he may have rubber-stampers in Congress doesn't mean he can do whatever he wants and be above the law.