FRANKSVILLE, Wis. - Rick Santorum reportedly grew heated and accused a New York Times reporter of distorting a statement he made in an earlier speech, even yelling "It's bulls-t" to him.

Jeff Zeleny of the New York Times tweeted, "I ask Santorum if Romney is 'worst Republican' to run. He says: 'Quit Distorting my words It's bulls-t.' He says he was talking health care"

During the speech, as he railed against Mitt Romney for his healthcare plan in Massachusetts, Santorum said the  former Massachusetts governor was the "worst Republican in the country" to take on President Obama.

"Pick any other Republican in the country. He is the worst Republican in the country to put up against Barack Obama," Santorum said at South Hills Country Club.

Santorum was asked by reporters to elaborate on what he meant by the categorization, and he insisted he was talking about the issue of healthcare.

"I would say as for on the issue of health care, yes, that's what I was talking about. 'Obamacare,' as you heard me say," Santorum said. "On the issue of health care. That's what I said. I didn't say anything different than that. That's exactly what I said."

Santorum increasingly grew agitated with the first group of reporters asking him to clarify his statement.

"On the issue of health care. That's what I was talking about, and I was very clear about talking about that. OK? C'mon guys, don't do this. I mean you guys are incredible," he said. "I was talking about 'Obamacare,' and he is the worst because he was the author of Romneycare."

The exchange with Zeleny occurred towards the end of the ropeline as Santorum finished greeting voters.

Asked by ABC News for a comment on Zeleny's tweet, the Santorum campaign sent a statement reiterating the candidate's criticisms of Romney.

A Romney campaign spokesman said Santorum is becoming "more desperate and angry and unhinged every day."

"He sees conservatives coalescing around Mitt Romney and he's rattled by the backlash caused by his suggestion that keeping Barack Obama would be better than electing a Republican," Romney spokesman Ryan Williams said. "He's panicking in the final stages of his campaign."