I feel the Kerry victory will be much larger than predictable by current polls, and the biggest deciding factor will not be particular issues but instead how happy people feel about voting. The thesis is that the happier that people feel about voting the more likely they are to vote.
By now, most Democrats feel that Kerry could make the world better off than the mess that resulted under Bush. They are happy that their vote can cause things to get better.
In contrast, the official Republican line is that things are about as good as can be expected. Their main motivation to vote is fear of Kerry: he will take all their money, let terrorists kill them, move the US toward godless communism, and mandate the teaching of sodomy techniques in public schools. They fear that if they don't vote things will go from good to worse.
On voting day, if you see long slow lines, go get some snacks to share with others and turn the wait into a party. There will be many happy people in line.