Running for the Senate in Massachusetts, Mitt Romney once assured voters in a state with strong gun-control laws: “I don’t line up with the NRA.” Now the likely Republican presidential nominee, Romney will headline the National Rifle Association’s annual convention Friday and assure tens of thousands of gun-rights activists that he’s squarely on their side.

Coming just days after rival Rick Santorum dropped out of the nomination race, the NRA convention in St. Louis provides Romney an opportunity to shore up his credentials with an important conservative constituency that badly wants to oust Democratic President Barack Obama.