Former U.S. Senator Rick Santorum suspended his White House bid on Tuesday, all but ceding the Republican presidential nomination to rival Mitt Romney.
"We made a decision over the weekend that while this presidential race for us is over for me, and we will suspend our campaign effective today," he said.
Santorum did not endorse Romney in making his announcement, though he did vow to fight to defeat President Obama and help Republicans win in the fall.
In a statement, Mitt Romney called Santorum "an able and worthy competitor" and congratulated his often-bitter rival for the formidable campaign he ran.
"He has proven to be an important voice in our party and the nation," said Romney.
"We both recognize that what is most important is putting the failures of the last three years behind us and setting America back on the path to prosperity."
Santorum's campaign insisted earlier in the day that he was not leaving the GOP race despite a decision to cancel his Tuesday morning campaign events.
His three-year-old daughter Bella, who suffers from a rare genetic condition called Trisomy 18, had been hospitalized again after falling ill over the weekend.
Santorum said that Bella recovered after a "difficult weekend," but that the situation "did cause us to think in the role that we have as parents in her life."
That, along with his dimming chances of overtaking Romney in the GOP delegate race, likely caused the unapologetic social conservative to pack it in.
Nevertheless, he leaves having won more than 10 states in the Republican nominating contest, pushing Romney longer than anyone possibly predicted.
Ron Paul and Newt Gingrich remain in the GOP race, but well behind Romney, who appears poised to finally finish this political war of attrition.
In a hypothetical matchup of the President and his likely GOP opponent, for whom would you vote if the election were today?