(CBS)-- When Rick Santorum ended his presidential bid on Tuesday, he spoke about the illness of his three-year-old daughter, Bella, and expressed a desire to spend more time with her as a parent. But on Thursday, the former Pennsylvania senator suggested the decision largely came down instead to a simple reality: He was out of cold, hard cash.
After losing Wisconsin's April 3 primary to rival Mitt Romney by seven points - a contest, Santorum said, that his campaign viewed as necessary to win in order to do well in his home state of Pennsylvania - his fundraising dried up.
"For the first time the campaign had a debt, the debt was from my perspective a little bit more substantial than I was comfortable with. And I'll be honest with you, Tony, in the last week after Wisconsin we basically raised almost no money," Santorum told Family Research Council President Tony Perkins in a radio interview, his first since announcing he was ending his bid. "We had solicitations going out and people were just emailing back saying the race is over and you gotta join the crew and there were others who would say not but it was a very, very small trickle of funds that were coming in."
Looking ahead to the Pennsylvania primary on April 24, Santorum said, he felt like his campaign wouldn't be able to spend even "a penny" on advertising to counter Romney's planned multi-million dollar advertising blitz.
The fundraising dried up as speculation mounted that Santorum couldn't stop Romney from securing the nomination - creating a narrative that Santorum said became impossible to overcome. The former senator quipped to Perkins that he was asked "when are you getting out?" more than people said, "hello." But he admitted that the notion of Romney's inevitability was due, in part, to his rival's success at controlling the media narrative.
"The media does drive this a lot more than people realize, they do in fact have the ability to drive a narrative beyond the campaign's ability to really to do much about it," he said. "In that respect I give Governor Romney a lot of credit in that he was more able to effectively spin the media effectively to drive his narrative than we were, and that's, that was just the reality of the situation."
Also playing into Santorum's thinking was the fact that it was becoming clear that he could not keep Romney from reaching the magic number of 1,144 delegates before the convention. The Republican National Committee had sent a firm message that they were not going to allow Texas to change its delegate allocation to a winner-take-all system, a move that could have benefitted Santorum's campaign. And once Romney amassed 89 delegates to Santorum's nine during the Wisconsin, District of Columbia and Maryland primaries, according to CBS News delegate counts, Santorum said, "it just seemed unlikely, not even unlikely but reaching to the point of impossible for us to be able to stop Romney" from reaching 1,144 delegates.
Although Santorum has pledged to support the Republican nominee, which is all but certain to be Romney, he does not seem ready to begin campaigning for his onetime foe and didn't even mention Romney's name during the interview. Instead, he said he planned to spend his time between now and November helping conservative candidates across the country achieve more prominence as elected officials and in a national debate.
He continued to bemoan his party's preference for moderate Republicans in many elections, a sign he may not yet have come to terms with Romney's victory.
"For conservatives we have to get conditioned to understand that you're going to be fed a steady diet of establishment candidate as long as we go along with the ideas that winning is what matters and not what is the right issues to go out and win with," Santorum said.
They were the words of a candidate who may be out of the 2012 race, but who is certainly not done fighting for his cause.