WEST MONROE (AP) — Facing heightened pressure to revive his presidential bid, Rick Santorum was forced to explain another apparent misstep as he courted Louisiana voters Friday, the eve of a critical contest in a Republican nomination battle that increasingly favors Mitt Romney.

Santorum said he would support the eventual GOP nominee — if it isn’t him — despite what he insists are similarities between front-runner Romney and President Barack Obama that make them indistinguishable on some issues. He caused an intraparty uproar earlier in the week after suggesting he’d prefer a second term for Obama over a Romney presidency.

“I’ve said repeatedly and will continue to say, I’ll vote for whoever the Republican nominee is and I will work for him,” Santorum said as he walked back his original comments less than 24 hours before Louisiana polls were set to open. “Barack Obama is a disaster, but we can’t have someone who agrees with him on some of the biggest issues of the day.”

The situation underscored Santorum’s challenges ahead of a Louisiana contest he’s favored to win. Santorum has had success in the South, having won last week’s contests in Alabama and Mississippi. Regardless of the outcome Saturday, however, Romney will have collected more delegates than his opponents combined as the race then turns to more favorable territory in the coming weeks.

Santorum’s continued missteps are complicating a candidacy already struggling to overcome major financial and organizational deficiencies. Before losing this week’s Illinois primary, Santorum hurt himself by declaring that neither the economy nor the nation’s unemployment rate was his top concern.

“I think the biggest development of the last 24 hours was Sen. Santorum’s remarkable mistake in suggesting that re-electing President Obama was acceptable under any circumstance,” Republican contender Newt Gingrich told reporters in Port Fourchon, La. “I just want to make very clear that I could not disagree with him more strongly.”

And as his GOP opponents fought amongst themselves, Romney went after Obama on the second anniversary of his landmark health-care law, previewing a key argument in a potential general election matchup.

Standing in front of signs that read, “Repeal & Replace ObamaCare,” as he campaigned in Louisiana, Romney called Obama’s signature health care law an “an unfolding disaster for the American economy, a budget-busting entitlement and a dramatic new federal intrusion into our lives.”

In attacking the law days before Supreme Court arguments over its constitutionality, the front-runner for the Republican presidential nomination also confronted an issue that has plagued him throughout the GOP primary process. As governor of Massachusetts, Romney signed a health care law that required everyone in the state to carry health insurance or pay a penalty. It’s a state version of the national mandate that is the centerpiece of Obama’s overhaul — an idea that conservatives oppose as an example of government overreach.

Romney’s steadfast support for the mandate at the state level has fueled continued conservative skepticism about his candidacy. And his attack on Obama’s overhaul caught the attention of White House spokesman Jay Carney, who said Friday that the president would “not shy away from the opportunity to debate” the bill, particularly given Romney’s background.

“That debate will be engaged in the fall if the Republican nominee feels so strongly about it,” Carney said, referring to Romney as “one of the architects of this health care reform.” “As many have noted in both parties, the individual mandate provision of the president’s Affordable Care Act bears striking similarities to the individual mandate that was put in place in Massachusetts.”

Meanwhile, Obama catapulted the death in Florida of 17-year-old Trayvon Martin, already the focus of major national attention, into the presidential campaign.

“If I had a son, he’d look like Trayvon,” Obama said.

Santorum was critical of local prosecutors, who declined to arrest the shooter, George Zimmerman, a 28-year-old neighborhood watchman who claimed self-defense and invoked Florida’s’ “Stand Your Ground” law. The law gives people wide latitude to use deadly force instead of retreating during a fight and explains why Zimmerman has not been arrested.

The failure to prosecute is a “chilling example of the horrible decisions made by people in this process,” Santorum said. “Stand your ground is not doing what this man did.”

Gingrich also criticized the shooter, whom he described as “a guy who’d found a hobby that’s very dangerous.”

Romney, like Obama, called the incident “a tragedy,” and called for “a thorough investigation that reassures the public that justice is carried out with impartiality and integrity.”

While attention to Martin’s death overshadowed presidential politics at times Friday, Santorum tried to keep the pressure on Romney ahead of the Louisiana contest. Santorum argued that he is the only Republican candidate who can offer voters a stark contrast with Obama.

After testing his marksmanship with a .45 caliber semiautomatic Colt pistol, he told reporters: “If you don’t have a choice, then a lot of voters are going to vote for what they have. That’s why we have to have a choice.”

Romney heads into Louisiana with a commanding delegate lead in the race to 1,144, the number needed to clinch the GOP nomination.

Romney has earned 563 delegates so far, compared to 263 for Santorum, 135 for Gingrich and 50 for Ron Paul, according to an Associated Press tally.

Louisiana offers a total of 46 delegates, but only 20 will be up for grabs in Saturday’s primary. An additional 23 will be selected at the party’s state convention in June and three others go to the state’s Republican National Committee members.

And while Santorum tried to recover from one misstep, a supporter in the audience added an off-message wrinkle. As he fired the pistol, a woman in the crowd shouted: “Pretend it’s Obama.”

Santorum was wearing protective ear muffs. He said later that he didn’t hear the remark but denounced it as “absurd.”

The Secret Service, which provides security for Santorum, was trying to identify the woman.


Associated Press writer Kasie Hunt from Louisiana contributed to this report.