GETTYSBURG, PA. — Bowing to the math of the moment, Rick Santorum ended his ailing presidential campaign Tuesday, virtially ensuring that Mitt Romney will be the Republican nominee in November.

“We made a decision over the weekend, that while this presidential race for us is over, for me, and we will suspend our campaign today, we are not done fighting,” the former U.S. senator from Pennsylvania announced in a speech here.

Santorum’s surprise move came one day after his disabled daughter Bella was released from a hospital in Virginia, where Santorum now lives.

Bella, who suffers from a rare genetic condition called Trisomy 18, had been hospitalized over Easter weekend. After much “prayer and thought” at home, Santorum said, he and his wife, Karen, and children decided it was time to end the campaign.

Saying he had enabled “conservatives to have a voice” in the GOP nominating process, Santorum marveled at the long-shot nature of his campaign, in which he rose to become the strongest remaining challenger to Romney.

“Miracle after miracle, this race was as improbable as any you will ever see for president,” he said. “We are not done fighting.”

Santorum did not mention Romney in the speech, and spoke instead of his gratitude for his supporters.

John Brabender, Santorum’s chief strategist, confirmed that Santorum talked to Romney before halting his campaign, and will be meeting with the likely nominee “in the near future”

Brabender stopped short of saying whether Santorum will officially endorse Romney.

In a statement, Romney said, “Senator Santorum is an able and worthy competitor, and I congratulate him on the campaign he ran. He has proven himself to be an important voice in our party and in the nation.

“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,” he said.

In announcing his decision, Santorum spoke of being “fueled” by the stories and struggles of ordinary Americans he had met on the campaign trail, particularly the parents of “special-needs” children who were inspired by Bella and Santorum’s role in fighting abortion.

“We were winning,” Santorum said, despite the pundits who had said he would never been the nominee.

“We were winning in a very different way, because we were touching hearts and we were raising issues that frankly people didn’t want to have raised,” he said.