The only constant in the Republican primary is that most of the candidates have enjoyed, and lost, a surge in the polls.
In early summer Rep. Michele Bachmann, after her win in the Iowa Straw poll, was the flavor of the month. This past fall, pizza man Herman Cain vaulted to the top tier. Newt Gingrich, former Speaker of the House, was briefly the leader of the pack. Now, with the caucus only days away, Sen. Rick Santorum is riding a wave of support.