Moving from First Pass the Post voting to a Single Transferable or Instant-runoff voting system would counter the spoiler effect (http://en.wikipedia.org/wiki/Spoiler_effect) allowing room in the american political system for strong third party candidates that won't hurt other close political parties and allow voters to select candidate they would most like to see elected not just the candidate they think has the best chance to be elected (http://en.wikipedia.org/wiki/Tactical_voting).
First Pass the Post
http://en.wikipedia.org/wiki/First-past-the-post
http://www.youtube.com/watch?v=s7tWHJfhiyo
Single Transferable Vote
http://en.wikipedia.org/wiki/Single_transferable_vote
Instant-runoff
http://en.wikipedia.org/wiki/Instant-runoff_voting
http://www.youtube.com/watch?v=3Y3jE3B8HsE