The Arizona primary will take place on Tuesday and 29 delegates are up for grabs.
Mitt Romney is favored in the Grand Canyon State contest. Arizona Gov. Jan Brewer (R) endorsed the former Massachusetts governor in the race for the Republican presidential nomination over the weekend.
The Michigan primary will also take place on Tuesday. Rick Santorum is hoping to score an upset win in the state where Romney was born.
Check out the live blog below for the latest developments out of Arizona and Michigan.