Their sparring is likely to intensify given the results of the latest Des Moines Register/Bloomberg News poll Saturday showing Cruz surging ahead of Trump in Iowa, 31% to 21%. The two will face off Tuesday in Las Vegas at the next Republican presidential debate, sponsored by CNN.”He’s been so nice to me. I mean, I can say anything, and he said, ‘I agree, I agree,'” Trump said.

Fulfilling his prediction, Trump called Cruz “a little bit of a maniac” in a separate interview, aired on Fox News Sunday.

“You can’t walk into the Senate and scream and call people liars and not be able to cajole and get along with people,” he said.

Trump said his professional success proves that he has “Great” judgment.

READ: National poll: Trump leads; Cruz rises, as Carson falls.

“It’s a strong temperament, but you know when they chop heads off of Christians in the Middle East, and other people also. When they chop off heads, and when they treat people the way – we’re like Medieval times. Having a strong temperament is good.”

Trump told Tapper that voters should pick him over Cruz because he’s “More capable” to lead the country and that he gets along with people “Much better” than Cruz.”I’m more capable. Because I have a much better temperament. Because I actually get along with people much better than he does,” he said.

“You know people don’t know that about me – I actually have a great relationship with people. In fact, I was criticized in the beginning because I get along with Democrats and liberals and Republicans, and conservatives – I get along with everybody.”

Cruz, on the other hand, does not get along with everybody, Trump said.

Ted Cruz