Rick Santorum Suspends Presidential Campaign Former Senantor Trails Mitt Romney, Has Taken Time Off With Ill Daughter

 -- Former Pennsylvania Sen. Rick Santorum suspended his presidential campaign today in a speech to supporters in his home state.

The announcement comes the day after Santorum's 3-year-old daughter Bella was released from the hospital -- her second trip this year. Bella suffers from a rare and often fatal disorder called Trisomy 18.

"This was a time for prayer and thought over this past weekend," Santorum said. "Just like it was when we decided to get into this race... we were very concerned about our role of being the best parents we possibly could to our kids," Santorum said of the kitchen-table discussion with his family before he launched his campaign.

Santorum said he balanced his desire to be a good father with his desire to do something positive for the country. He mentioned Bella and her condition as one of the reasons he joined the race -- to look out for Americans like her, who he said are "left behind."

"While this presidential campaign is over for me, we are going to continue fighting for those voices," Santorum told a sedate crowd in Gettysburg, Pa.

Santorum waged a scrappy and unexpectedly strong campaign for the Republican nomination, essentially moving to Iowa before narrowly winning the caucus there. Barely registering on opinion polls throughout 2007, he was the first candidate to visit all of the state's 99 counties. He built his campaign around engaging audiences in townhall meetings, often wearing a sweater vest and uttering his campaign battle cry, "Game on."

But like many of his stronger showings in the primaries, Santorum's Iowa victory was marred by some bad luck; party officials there initially called Mitt Romney the narrow victor on caucus night, only to later give the nod to Santorum.

In total, Santorum has won 10 presidential preference contests. That's one fewer than Romney carried in his losing bid in 2008. Santorum has recently compared his current run to Ronald Reagan's 1976 bid. Reagan carried his attempt to unseat President Gerald Ford all the way to the Republican convention that year. Ford eventually got the nomination, but lost the general election to Democrat Jimmy Carter. Reagan was the Republican nominee four years later in 1980 and became a two-term president.

"Miracle after miracle this was race as improbable as any race you will ever see for president.," Santorum said today.

See how Santorum did in each contest so far.

Santorum became the main conservative alternative to Romney, but Romney and his allies outgunned Santorum in television advertising and out-maneuvered him in the delegate race.

Party elders had begun to coalesce around Romney and urged Santorum to end his campaign in recent days. Everyone from former President George H.W. Bush to Florida Sen. Marco Rubio and Tea Party Leader Sen. Jim DeMint had urged Republicans to view Romney as the party's choice.

Santorum didn't mention Romney or the need to coalesce as he ended his campaign, focusing instead on his family.

Romney, in a statement, said Santorum had been an able competitor.

"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," wrote 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 move makes Romney, the former Massachusetts governor who has a commanding delegate lead, the all but certain Republican nominee, although Newt Gingrich and Ron Paul both remain actively in the race.

Gingrich praised Santorum in a statement, but said he has no plans to leave the contest before the Republican convention in Tampa, Florida.

"I am committed to staying in this race all the way to Tampa so that the conservative movement has a real choice."

RNC Chairman Reince Priebus praised Santorum for ending his campaign.

"Today, Senator Santorum has made a commendable decision," Priebus in a statement. "He has decided to put his country, party, and desire to defeat President Obama ahead of any personal ambition. I applaud his decision and congratulate him on the campaign he has run." ABC's Primary Scorecard

Read more about Rick Santorum.

ABC News' Arlette Saenz reported from Gettysburg, Pa.