One reason the Republican presidential contest has been so unusually volatile is that it's become two races running along parallel but very distinct tracks. One of those races seems to be settling down, steadily if slowly. The other still appears perched on an earthquake fault. If that dynamic persists, former Massachusetts Gov. Mitt Romney will remain the favorite for the nomination- even though a significant proportion of the party remains resistant to choosing him.
The evolution of the GOP contest into two distinct races becomes apparent when looking at the long trend in public opinion polling. In the twelve national CNN/ORC surveys about the race conducted since January four different candidates have held or shared the national lead: ex-Arkansas Gov. Mike Huckabee and businessman Donald Trump (neither of whom actually entered the race), Romney and Texas Gov. Rick Perry. Other national polls this year have recorded leads for former Alaska Gov. Sarah Palin and more recently businessman Herman Cain.