Former Sen. Rick Santorum announced Monday he will run for president in 2012 saying he would repair economic and moral damage he believes the country has suffered at the hands of the Obama administration.

Santorum said President Obama has devalued the U.S dollar and inflated prices on food and oil by borrowing and spending too many federal dollars to "prop up" the government.

"He's devalued our currency and he's devalued our culture through our marriage and through not standing up for the Defense of Marriage Act, through federal funding of abortions," Santorum said. "He devaluing our dollars and he devalues our other currency, our moral currency."

The Obama administration announced in February it would no longer defend the Defense of Marriage Act , a law that defines marriage as being between a man and a woman.

Santorum made his announcement at a rally at the Somerset County Courthouse in Somerset, Pa., near where his grandfather settled when he came to the United States from Italy.

Santorum served in the U.S. Senate from 1995 to 2007 and is a favorite among social conservatives, particularly for his stance against abortion and stem-cell research.

"We are ready to announce we'll be in this race and we'll be in it to win," Santorum said on ABC's Good Morning America during an interview before the rally.

While he has had some success in straw polls in the early primary states, Santorum still polls in the single digits, well behind GOP front-runner and former Massachusetts governor Mitt Romney who announced his run last week.

Asked by host George Stephanopoulos why he thought he could win the nomination when he lost his Senate seat to Democrat Bob Casey by 59% to 41% in 2006, Santorum said voters are looking for a candidate who " has stood by their principles in good times and in bad."

"In 2006, I think, in everyone's estimation, was a pretty bad time for a Republican, particularly for a conservative," he said on Good Morning America, adding that his commitment to social security reform also got him into trouble with voters that year.

"If you look back at what I did and when I did it, people can say... 'well he may have lost but he didn't flinch, he stood by what he believed in and he continued the fight to the end,'" he said.