I hate to give money to political parties because it is all wasted on things like advertising and supporting politicians I may not agree with purely to fight politicians I feel are evil. It also comes out of the charity money that I donate to worthy causes like aid for those in need and environmental causes. However, at times (i.e. the last election cycle, the evil to be fought is so extreme that I must do it and I did it. The first time that I gave more than a token amount of money to political campaigns. Sadly, this may need to be repeated.
"In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion." (1987) -- Carl Sagan