DES MOINES, Iowa (AP) -- From the start, it's been a roller-coaster race for the Republican presidential nomination. 

 

GOP primary voters can catch their collective breath for the next two weeks.  

The next contests, in Arizona and Michigan, aren't until Feb. 28. The party with a reputation for order may have it sorted out after March 6, when 10 states get their say. But that would break sharply with this race's tendency toward uncertainty.  

With nine contests down, Mitt Romney leads the delegate hunt, and has both the money and the organization to compete deep into the state-by-state nomination calendar.  

But his two main rivals have scored decisive victories, putting into doubt the strength of the former Massachusetts governor's front-running candidacy.