Rick Santorum leads the race for Louisiana - live primary coverage Rick Santorum speaks to USAA employees during a campaign stop at USAA in San Antonio. 11.38am: "Pretend it's Obama" - a crowd member's comment, not the candidate's. Here's a picture of Santorum at the firing range. Santorum has spoken before about his rules for managing or correcting an audience. In January a woman at a Florida Santorum event stood up and said of the president, "He is an avowed Muslim and my question is, why isn't something being done to get him out of our government?" Santorum responded: "Believe me ... I'm doing everything I can to get him out of the government. Later Santorum explained why he hadn't corrected the woman. "It's not my responsibility as a candidate to correct everybody who makes a statement that I disagree with," Santorum told reporters. There are lots of people who get up and say stuff in a town hall meeting and say things that I don't agree with, but I don't think it's my obligation, nor should it be your feeling that it's my obligation to correct somebody who says something that I don't agree with. 11.29am: As for Rick Santorum, he's hosting a rally at Ouachita Sheriff's Shooting Range in Monroe, La. The candidate is handling guns for the cameras. For better or for worse (let's just say for worse) this kind of posing has become the norm for American politicians courting the NRA vote. But the optics are different this morning. Santorum is at a shooting range and talking about fundamental freedom while the president is at the White House talking about the killing of an unarmed kid by a zealot packing a legal concealed firearm. A poignant juxtaposition - or maybe not; maybe just a meaningless accident of timing. But then someone in the audience at the firing range draws a connection that completes the circle - guns and politics and race and violence - urging Santorum preparing to fire at a target to "pretend it's Obama." Politico's Juana Summers is there: 11.16am: Let's check in on the candidates (still plural) for the 2012 Republican presidential nomination. For once they're easy to find: All four are in Louisiana, campaigning away in advance of tomorrow's primary. (Here's a stumper: When was the last time all four candidates were in one state together on the same day? Ron Paul is the tough one to pin down; remember he skipped Florida. Let's crowd source this: let us know in the comments when the last time was that the stars aligned this way and... and then we can all pat ourselves on the back.) Mitt Romney got off to a quick start this morning by taking the stump and committing embarrassing dad moment No. He dropped a "y'all" - and then stutteringly corrected himself and said he wasn't trying to pretend he was from Louisiana. Will there be a tipping point, after which Romney's helpless inability to avoid these kinds of awkward moments will become sort of endearing? 10.50am: Here is video of President Obama's remarks on the Trayvon Martin case. 10.31am: After announcing his pick for the new head of the World Bank, President Obama spoke about the case of Trayvon Martin, the black teen shot dead by a neighborhood watch zealot in Sanford, Florida. The shooter, George Zimmerman, was allowed to leave the scene of the killing and has not been arrested. My colleague Matt Williams has the president's remarks: Obviously this is a tragedy, we can only imagine what these parents are going through. And when I think about this boy, I think about my own kids and I think every person in America should be able to understand why it is absolutely imperative we investigate every aspect of this to find out exactly how this tragedy happened. All of us have to do some soul searching to discover how something like this happened. If I had a son he would look like Trayvon, and I think they (his parents) are right to expect that all of us as Americans will watch this with the seriousness it deserves and we will get to the bottom of this. Trayvon Martin rally in Florida. Photograph: Julie Fletcher/AP 10.22am: In an announcement at the White House moments ago, President Obama tapped Dartmouth President Jim Yong Kim to be the new head of the World Bank. Kim had not been widely named as a leading candidate for the post, but his selection was hailed as a creative and canny move by the president. Here's Slate economics writer Matt Yglesias: I still wish the Obama administration had gone outside the box and tapped a non-American to lead the World Bank, but their actual selection Dartmouth President Jim Yong Kim seems like a very strong dark horse candidate. As a former director of the Department of HIV/AIDS at the World Health Organization he has some of the necessary experience with international organizations, and his general expertise in the field of public health and infectious diseases is rightly focused on the area where development assistance has the clearest track record of success and potential for future gains. What's more, though he's lived in the United States since the age of 5, he was actually born in South Korea so there's at least a little crack in the door of the American monopoly on the Bank Presidency. Given that the developing world's two candidates for the job at the moment are coming from Africa and Latin America, nominating an Asian-American also seems like a potentially clever nod in the direction of Asia's rising importance in the global economy while maintaining the basic EU/US hegemony over the Bretton-Woods institutions. Jim Yong Kim, President of Dartmouth College. 10.15am: Good morning, it's Friday, a lovely day for politics. Tom McCarthy here in New York and welcome to our live blog coverage. My colleague Ryan Devereaux starts us off with a survey of the latest developments: Rick Santorum is on his way to a substantial victory in tomorrow's Louisiana tomorrow - that's the prediction of the Democratic polling organization Public Policy Polling. Their poll has Santorum up 42%-28% over Mitt Romney. Mitt Romney has an op-ed in USA Today calling for the repeal of the Affordable Care Act - known to its enemies as Obamacare - regardless of whether the Supreme Court strikes the legislation down. You can read it here. In 2009, Romney penned an op-ed in the same paper on the same issue, urging Obama to look to Massachusetts as a model. This time around, Romney has streamlined his argument. He writes, "When I was governor of Massachusetts, we instituted a plan that got our citizens insured without raising taxes and without a government takeover. Other states will choose to go in different directions. It is the genius of federalism that it encourages experimentation, with each state pursuing what works best for them. ObamaCare's disregard for this core aspect of U.S. tradition is one of its most egregious failings. The failed presidential campaign of Rep. Michele Bachmann is $1 million in debt. Maybe she can turn to Mitt Romney, who helped take care of former rival Tim Pawlenty's presidential campaign debt. Ron Paul has inserted himself into the Etch A Sketch controversy that has consumed the GOP race of late. In a powerful 41 second video posted yesterday, the Paul campaign suggests the growing concern over the child's toy might actually be less important than other "problems" facing the country right now. The ad asks the viewer, "Tired of the games? . . . Ron Paul 2012: A serious plan to restore America now.