Former Pennsylvania Sen. Rick Santorum this morning confirmed his plans to seek the presidency, announcing on “Good Morning America” that an 11 a.m. speech would serve as the official launch of a White House bid that has been under way for months.

“We’re ready to get into this race, and we’re in it to win it,” Santorum said on the ABC program.

The Republican has been out of elected office since suffering an 18-point drubbing at the hands of now-Sen. Bob Casey (D) in 2006. But he has been among the most active candidates early in the presidential contest, having visited key early states such as Iowa, New Hampshire and South Carolina dozens of times this year already. While he has attracted activists in some cases, winning straw polls, he’s yet to catch on in national polls.

Known for his cultural conservative credentials — particularly for outspoken positions on abortion and gay marriage — some conservative commentators have suggested that Santorum could be a factor in a crowded GOP field, especially if social issues become prominent in the 2012 debate. But with economic growth showing signs of stalling, Santorum’s opening, small to begin with, could be closing further (and his stance on gay marriage has been a particular problem over the years).

Still, he is taking his chances quite seriously. And the national media is giving him largely the same treatment as was given to the likes of top-tier candidates Mitt Romney and Tim Pawlenty.

Following his “Good Morning America” appearance, Santorum conducted a host of radio interviews, including one with Glenn Beck. He will formally launch his campaign from the Somerset County Courthouse in Somerset, Pa.

The location is significant, says his spokesman, because it’s close to where Santorum’s grandfather settled in America “after leaving fascist Italy to work in the Pennsylvania coal mines until he was 72 years old.”