A web application that would enable you to vote on why your are going to vote (bare with me here) for a particular president and to submit your reasoning, should such not be present. So it might go something like this:
– Why vote Bush?
– Why vote against Bush?
– Why vote Kerry?
– Why vote against Kerry?
Then, each reason has a rating (vote calculated, for instance), and an associated discussion forum so that people can add/remove their vote to/from a particular reason (establishment of credibility of argument). This is a simpler version of another system I really want to build (more on that some other time – am actually close to getting something resembling a prototype out).