MESA, Ariz. — A bitter and often personal debate behind them, Republicans Rick Santorum and Mitt Romney are shoring up their campaigns in different ways ahead of a series of crucial presidential primaries.
Romney is paying the most attention to Michigan, his birthplace and the site of an unexpectedly tight race with Santorum, by attending a tea party rally Thursday night in an effort to get more conservative support. He has campaigned confidently in Arizona, so much so that he has not aired any television ads in the state.
Santorum, meanwhile, is focusing for the moment on raising money for his cash-strapped operation. He is hoping for an upset in Michigan, which would cap a rebound that began two weeks ago when he won caucuses in Minnesota and Colorado and a nonbinding primary in Missouri.
The 20th debate of the primary season offered the GOP hopefuls their final face-to-face outing on a national stage before contests over the next 12 days that may well winnow the field. Arizona and Michigan host primaries Tuesday, followed by caucuses in Washington four days later. Ten states will cast ballots on Super Tuesday, March 6.
Polls show Santorum leading the field nationally and in several states. Romney and rivals Ron Paul and Newt Gingrich used the nationally televised forum Wednesday night to challenge Santorum, who repeatedly found himself in the hot seat over his record on spending, home-state projects known as earmarks, and support for a federal education law.
Romney criticized Santorum for support of spending programs when he represented Pennsylvania in Congress, where he served both in the House and Senate. Romney said Santorum voted five times to raise the government's ability to borrow, supported retention of a law that favors construction unions, and supported increased spending for Planned Parenthood. He said federal spending had risen 78 percent overall while Santorum was in Congress.
Santorum retorted that government spending declined as a percentage of the economy when he was in the Senate, and he noted that when Romney was asked last year if he would support a pending debt-limit increase, "he said yes."
The former Massachusetts governor also went after Santorum on earmarks, the specialized spending bills directed to a particular state or program.
"You voted for the Bridge to Nowhere," Romney said to Santorum, referring to an infamous bridge proposal in Alaska that would have been built with millions in federal funds. "I would put a ban on earmarks."
Paul went further, calling Santorum a "fake" conservative. Gingrich dismissed the argument over earmarks as "silly" but said his years as House speaker made him best equipped to bring reform to such Washington practices.
Santorum, for his part, said he had differentiated between "good earmarks and bad earmarks" and supported only those that funded defense and other needed projects.
He also noted that Romney had sought earmarks to fund the 2002 Salt Lake City Olympics. And he blamed Romney anew for championing a health care law in Massachusetts that became the prototype for President Barack Obama's health care law, which is detested by conservatives.
"It would be a difficult task for someone who had the model for Obamacare — the biggest issue in this race — to be the nominee of our party," Santorum said.
In rebuttal, Romney said Santorum actually bore responsibility for passage of the health care law that Obama won from a Democratic-controlled Congress in 2010, even though he wasn't in office at the time. Romney said that in a primary battle in 2004, Santorum had supported then-Sen. Arlen Specter of Pennsylvania, who later switched parties and voted for the law Obama wanted.
Santorum also took his lumps from the audience, which booed when he said he had voted several years ago for the No Child Left Behind education legislation even though he had opposed it.
"Look, politics is a team sport, folks," he said of the measure backed by Republican President George W. Bush and other GOP lawmakers.
In the hours leading to Wednesday night's debate, Romney called for a 20 percent across-the-board cut in personal income taxes as part of a program he said would revitalize the economy and help create jobs. The top tax rate would drop from 35 percent to 28 percent, and some popular breaks would be scaled back for upper-income taxpayers. However, aides provided scant details.
"We've got to have more jobs, less debt and smaller government, they go together," Romney said in an appearance in nearby Chandler.
Santorum's rise in the race has left Paul and Gingrich on the outside looking for a way in.
Paul has yet to win any primaries or caucuses. He is airing an ad in Michigan, though, that challenges the Santorum's claim of taking a conservative line against federal spending.
Gingrich, the former Georgia congressman, is pinning his hopes for a comeback on that state on March 6.
His campaign announced plans Wednesday to buy 30-minute blocks of television time in upcoming primary and caucus states for an infomercial on reducing energy prices.
In all, 518 Republican National Convention delegates are at stake between Feb. 28 and March 6, three times the number awarded in the states that have voted since the beginning of the year. It takes 1,144 to win the nomination.
Fouhy reported from Washington. Follow her on Twitter at www.twitter.com/bfouhy
Follow Kasie Hunt on Twitter at www.twitter.com/kasie