High stakes for Rick Santorum at tonight’s GOP debate

The last time the four remaining contenders in the GOP presidential race met on a debate stage, all eyes were on Newt Gingrich, who was trying to ride the momentum off his surprise victory in South Carolina.

On Wednesday night, the spotlight turns to Rick Santorum.

In a race that has seen a cast of not-Mitt Romney characters take turns challenging the sometimes-front-runner, Santorum is on his second surge. He won the Iowa caucuses, albeit by a tiny margin and weeks after Romney was initially declared the winner. But his candidacy faded into the background as Newt Gingrich rose in South Carolina.

After scoring a trifecta of victories in caucuses in Colorado and Minnesota and a beauty contest primary in Missouri earlier this month, Santorum is back on top, vying with Romney for first place in national polls and in the upcoming primary states of Arizona and Michigan.

For the Pennsylvania senator, Wednesday’s CNN debate in Mesa, Ariz., offers an opportunity to reposition himself as not just a fringe candidate and a chance to earn some much-needed free media exposure. It is also potentially dangerous: With rivals Ron Paul and Newt Gingrich eager to climb into the top tier, they’re likely to aim their attacks at Santorum as he focuses his fire on Romney. That could make for a vicious three-on-one fight.

Watch for moderator John King to steer the debate toward topics like immigration and the economy, key issues for voters in Arizona and Michigan, the states that will hold their primaries Tuesday. Other potentially explosive topics include abortion, birth control and healthcare.

Arizona is territory that should be friendly to Romney. He placed second there behind John McCain in 2008 and scored the Arizona senator’s endorsement earlier this year. Then again, Romney won states such as Colorado and Minnesota in ‘08, only to see Santorum claim victory this time around.

Recent polls in Arizona show Romney losing ground to Santorum, whose appeal to social conservatives has forced Romney to position himself further to the right than might be believable. Many voters still see him as a moderate former governor of a liberal state, Massachusetts.

With no debates scheduled until well after Super Tuesday, Wednesday’s event could be the last time all four candidates share a debate stage. The show starts at 5 p.m. PST.

kim.geiger@latimes.com