It has nothing to do with party membership, but the opposing views of the other party. It was a shorter way to say, "He had different views and stances on the things than I do, therefore, I disagree with him and will nit-pick what I can because 'I can do it better.'" Damn, I didn't think it was difficult to follow that line of thinking, but I guess I was wrong. You voted Democrat, didn't you?