Donald Trump: "I don't understand Iowa"

Donald Trump: “I don’t understand Iowa”... 00:47

As Ben Carson catches up to Donald Trump in Iowa in recent polls of the early contest state, Trump remains baffled at his Republican competitor's success.

"I don't understand Iowa because frankly, I just left and we had tremendous crowds and tremendous enthusiasm," Trump told CBS' "Face the Nation" early Sunday. "Frankly, even to be tied, I'm a little surprised."

He added that he was "very honored" to be lead in other key early-voting states like New Hampshire and South Carolina. But when it comes to Iowa, where he and Carson both lead the GOP field at 27 percent in a new CBS poll, he remains "surprised."

"I think that Iowa, you know, it has that same incredible feeling. We had a rally there the other day and it was so intense and there was so much love in the room," Trump continued. "So I'm actually surprised, very surprised that I'm even tied in Iowa."

Trump attributes Carson's rise in Iowa to the super PAC operations backing Ben Carson in the state, which he attacked as "running Iowa for him."

Trump says his comment on Carson’s religion... 02:30

"The people running his PAC are highly trained professionals I would imagine. And those people are using that PAC differently than you're supposed to use a PAC," Trump said. "They are running Iowa for him. They are in there. They're doing all sorts of things that are totally different than what you're supposed to be doing.

"Ben is in Iowa very little. He does not go to Iowa much," Trump continued, accusing the retired neurosurgeon's super PAC supporters of conducting the battleground fight for him in his stead. "They're essentially campaigning for him in Iowa and that's not what a PAC is supposed to be, it's not supposed to happen that way."

He knocked the idea of super PACs in general, saying that "this whole PAC concept is fraught with problems and I think you're going to see tremendous problems with PACs over the years."

Trump also addressed comments he made in Florida the day before against Carson's religion, the Seventh Day Adventists.

To a Jacksonville crowd on Saturday, Trump had said: "I'm Presbyterian. Boy, that's down the middle of the road folks, in all fairness. I mean, Seventh-day Adventist, I don't know about. I just don't know about."

On "Face the Nation," Trump explained that he meant what he said: "I don't know about them. I don't know about what that is."

"I'm not that familiar with it," he continued. "I've heard about it, but I'm not that familiar with it."

He added that it "wasn't meant to be an insult." -- rather, it's "just that I don't know about it."

Trump aimed additional attacks at rival Jeb Bush, whose campaign operations are slashing staff salaries by 40 percent across the board and undergoing a complete restructure.

Donald Trump: Jeb Bush’s campaign is a “t... 01:10

"His campaign is in disarray," Trump said. "He's languishing way, way back in the pack."

When asked about the upcoming debt ceiling debate in Congress, Trump criticized outgoing House Speaker John Boehner for the congressman's promise to pass a "clean" debt ceiling increase.

"John Boehner said the other day he will not use the debt limit, he will not close," Trump said. "Well, I'll tell you what: When you say that, you have now given everything to the Democrats and to President Obama because they have their way 100 percent."

Instead, Trump would want to use the possibility of a debt limit increase as a "negotiation" tool.

"Boehner should not be saying, 'We will not close,' because you can't negotiate once you say that," he added. "You've given up 95 percent of your strength when you do that."

When pressed, Trump would not say whether he would increase the debt limit, but he considered it an "amazing" weapon in Congressional Republicans' arsenals.

"I will tell you, it's an amazing tool to negotiate because it is a very, very -- I mean, it is fairly catastrophic if it happens," he said. "But some people are willing to go through that in order to win."