Bush did a great job by letting Kerry show his contempt for the Constitution.
Kerry said that he would appoint justices who would interpret the Constitution according to the law.
They are supposed to interpret the law according to the Constitution.
Yes, so Bush should have pointed out that Kerry judges are the type who would use their ideology to interpret the Constitution. Kerry judges would read the Constitution and come away declaring that it requires gay marriage, bars the most reasonable restrictions on abortion, etc.
He needed to include some concrete, specific examples to go along with the sound conceptual response he gave. He needs to put a face on the concept.