"I'm ready to do what has to be done for the next generation, with the courage to fight for freedom, with the courage to fight for America," Santorum said in Somerset, surrounded by his wife and seven children. "That's why I'm announcing today that I'm running for president."
Santorum said he wants to steer America back to having the kind of freedom his coal miner grandfather enjoyed after he fled Italy under Benito Mussolini, Politico reported.
"That's the American that he came to, that's the American he believed in, and that's the America we need today," Santorum said.
President Obama's healthcare reforms harm that freedom and are a way of shackling Americans to more entitlements.
"They want to hook you," he declared. "They don't want to free you. They don't want to give you freedom. They don't believe in you. They believe in themselves, the smart people, the planners."
Santorum's speech encompassed economic and social issues in its indictment of Obama's presidency.
"He's devalued our currency, and he's devalued our culture," Santorum said.
Santorum announced his candidacy earlier on ABC's "Good Morning America," saying, "We are ready to announce that we are going to be in this race and we're in it to win."
Santorum, who already visited several early primary/caucus states, trails in early polling. The latest Gallup poll indicated he was at 2 percent, well behind former Massachusetts Gov. Mitt Romney's 19 percent, former Alaska Gov. Sarah Palin's 15 percent and Texas' U.S Rep. Ron Paul's 13 percent.
Since losing his Senate seat to Bob Casey in 2006, Santorum has been a senior fellow at the Ethics and Public Policy Center. He was a Fox News analyst until the network suspended his contract while he mulled his plans for 2012.