SOMERSET, Pa. - Former Pennsylvania Sen. Rick Santorum formally launched his campaign for president Monday, offering himself as a tested leader with the "courage to fight for freedom . . . to fight for America" against the power of an expanding social-welfare state.

"President Obama took that faith that America gave him and wrecked our economy and centralized power in Washington, D.C., and robbed people of their freedom," a smiling but combative Santorum told several hundred supporters jammed on the plaza of the Somerset County Courthouse.

A former two-term senator who lost his seat in 2006 to Democrat Bob Casey by 18 percentage points, Santorum has been most known in his career as a leader of social-issues conservatives, but the case he built against Obama on Monday was mostly economic and spiritual, in the sense that Santorum argued an increased reliance of citizens on government threatens the national character.

"I believe now that Americans are not looking for someone that they can believe in - they're looking for a president who believes in them," Santorum said.

The Republican said he chose the spot for his announcement for its symbolic power. Santorum said his grandfather Pietro worked as a coal miner in nearby Carpenter's Park in 1927, after emigrating from Italy, where he had a prosperous life working for the government under Mussolini - but wanted freedom.

Somerset also is not far from where a group of citizens tried to wrestle Flight 93 from terrorists bent on attacking Washington on Sept. 11, 2001, and crashed it into the ground near Shanksville.

So far, Santorum has languished in the single digits in polls of the Republican race, but he has made more trips to Iowa, New Hampshire, and South Carolina than any other candidate, and he has an opening to consolidate evangelical voters behind him now that former Arkansas Gov. Mike Huckabee, a Baptist minister, has decided not to run.

Of course, there is potential competition for that vote from Sarah Palin and Rep. Michele Bachmann of Minnesota.

As he has on the campaign trail in New Hampshire and South Carolina, Santorum said the "linchpin" of efforts to erode personal freedom was Obama's health-care overhaul, which requires people to buy health insurance.

"Why do you think they ignored the polls and jammed it down the throats of the American people?" Santorum said. "Power. . . . They want to hook you, they don't want to free you.

"They don't want to give you opportunity. They don't believe in you. They believe in themselves, the smart people, the planners, the folks in Washington who can make decisions better than you can."

He was flanked by his wife, Karen, and their seven children at a political rally with echoes from an earlier time, before candidates announced for president on Facebook and Twitter, with balloons (several of which popped during the festivities, startling some in the audience), flags, and a jazz band.

"I approve of what he thinks about keeping government small, and his moral standards," said Larry Remple, 63, a Santorum supporter in the crowd, who owns a business in Confluence, Pa. "I hope people are stirred up enough to get behind him. I trust his judgment."

A few blocks away, waiter Gary Bartko said he was leaning toward Mitt Romney, the former Massachusetts governor, saying his business experience could help get the United States out of its recession.

A Republican, Bartko, 27, voted for Santorum for the Senate. As a presidential candidate, "he's too conservative for me and has no personal skills. He doesn't know how to talk to people."

Shopping at Wal-Mart on the edge of town, Bonnie Kelly said she worked in a garment factory until it was shuttered and operations were moved to Mexico several years ago.

It would be good to "have someone from our backyard who knows this depressed area," Kelly, 58, said, speaking of Santorum. "The American people have nothing, no industry here."

Jon Tucker, 57, knows that well. He was a steelworker for 12 years and now works at a Giant Eagle supermarket in maintenance. "The job situation is poor here, and the gas prices are high. I can't afford to go anywhere," he said. Tucker is undecided in the presidential race but said he wanted somebody, anybody, who could improve the economy.

Read his blog, "The Big Tent,"