April 10, 2012 -- Former Pennsylvania Senator Rick Santorum suspended his presidential campaign Tuesday, a source close to the campaign confirmed to ABC news.
The news comes the day after Santorum's 3 year-old daughter Bella was released from the hospital - her second trip this year. She suffers from a rare and often fatal disorder called Trisomy 18.
Santorum waged a scrappy and unexpectedly strong campaign, essentially moving to Iowa before narrowly winning the caucus there. But like many of Santorum's stronger showings in the primaries, his Iowa victory in Iowa was marred by some bad luck; party officials there called Mitt Romney the narrow victor on caucus night and later gave the nod to Santorum.
He went on to become the main conservative alternative to Romney. But Romney and his allies outgunned Santorum in television advertising and outmaneuvered him in the delegate race.
Santorum's move makes former Massachusetts Gov. Mitt Romney, who has a commanding delegate lead, the all but certain Republican nominee, although Newt Gingrich and Ron Paul both remain actively in the race.