Donald Trump has a problem with Rick Santorum's run for president.
"I have nothing against Rick Santorum," the billionaire said in a YouTube video released Wednesday. "But what someone has to explain to me is, how can somebody who is a sitting senator run for the Senate as an incumbent and lose by 19 points to somebody else, and then say, 'Well, gee, I just lost in Pennsylvania for the Senate by 19 points, now I'm going to run for president'? Explain that to me."
The video comes on the heels of Santorum's three-state sweep on Tuesday, in which he pulled an upset win in Missouri, Minnesota and Colorado, edging out GOP front-runner Mitt Romney.
But The Donald, who has endorsed Mitt Romney, portrayed the sweater-vest-wearing former Pennsylvania senator as a political loser.
"It's like, as an example, you're a high school student," Trump said. "You flunk out of high school, you're out. And you say, 'You know what? I think now I'm going to apply to the Wharton School of Finance. I want to go to the Wharton School.' It doesn't work that way."
