The bible is my authority. Read Eph. 5:11 and 1Cor 2:15:
And have no fellowship with the unfruitful works of darkness, but rather reprove [them].
It is right and correct and biblical to expose Bush's anti-Christian statements and activities. The bible also says, But he that is spiritual judgeth all things, yet he himself is judged of no man. (1Cor 2:15)
We must judge, the key is we are not to judge self-righteously (Ro. 2:1). If we didn't judge, we could not administer church discipline properly. I do not think it is self-righteous judgment to hold Bush's feet to the fire for his errors. It is not just one error - it is a whole bunch of them (did you read the website?), which indicates a pattern - a pattern of un-Christian or anti-Christian behavior and talk. He to be a Christian - he has made public statements to this effect - yet his actions do NOT reflect it.
Bottom line: Christians are called to Holy in all they do - including their vote, and voting for a candidate that does not represent biblical values is an error from a biblical standpoint. There are more than 2 parties. I refuse to be a prisonor of the 2-party system. It will change!