Polls have begun closing in the Michigan Republican presidential primary, where former Massachusetts governor Mitt Romney and former Pennsylvania senator Rick Santorum are locked in a close race, with Romney hoping to reestablish himself as the frontrunner and Santorum hoping to gain momentum and reinforce his claim on the party’s conservative base. Arizona today also is holding its Republican primary, where all 29 delegates are expected to go to Romney. The state has a winner-take-all primary so most candidates conceded the race to Romney, who held his lead in the polls. Polls began closing at 8 p.m. Eastern Time in Michigan. They were to begin closing at 9 p.m. Eastern Time in Arizona/Matt Viser and Bobby Caina Calvan, Boston Globe. More here. (AP photo: Karen Santorum lists to her husband talk to the media in Grand Rapids, Mich.)

Question: Predictions?