Former Pennsylvania Senator Rick Santorum looks likely to win the Louisiana primary, racking up another victory in the Republican race to challenge President Barack Obama. A win by Santorum would serve as a reminder that Romney still struggles among the Republican party's conservative faithful, especially in the South. Santorum beat front-runner and former Massachusetts Gov. Mitt Romney in primaries in Alabama and Mississippi earlier this month. But regardless of Saturday's outcome, Romney will still have collected far more delegates than all his opponents, creating a juggernaut that looks increasingly unstoppable. Increasingly, powerful members of the Republican establishment have been coming forward to back Romney in his bid for the White House and trying to put an end to a longer-than-expected primary race that has left the candidates and even the entire Republican party badly bruised. Still, Santorum tried to keep the pressure on Romney Friday ahead of the Louisiana contest, arguing that he is the only Republican candidate who can offer voters a stark contrast with Obama. “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,” Santorum said after testing his marksmanship with a .45 caliber semiautomatic Colt pistol. Santorum, however, was forced to explain another apparent misstep, saying he would support the eventual Republican nominee — if it isn't him — despite what he insists are similarities between Romney and Obama that make them indistinguishable on some issues.