Anderson Cooper. CNN/screenshot CNN anchor Anderson Cooper grilled Sen. Ted Cruz of Texas on Tuesday over his assertion last year that Donald Trump is "terrific."

During a CNN town-hall event, Cooper asked Cruz whether he made a "political calculation" not to go after Trump, citing a tweet in December in which Cruz said that Trump was "terrific."

Cooper pointed out that Trump had already caused a number of notable political firestorms by that point.

"That was after he had already made fun of Carly Fiorina's face. That was after he had gone after Megyn Kelly. At that point in December, did you really believe that Donald Trump was terrific?" Cooper asked.

Cruz did not address whether he believed that Trump was terrific. He instead criticized media outlets for allowing Trump such a large platform.

"Look, what I knew is that the media was engaged in a lovefest, giving Donald Trump $2 billion in free media," Cruz said, citing a recent New York Times study showing Trump's dominance of so-called free media coverage.

"It sounds like you were engaged in a lovefest, though," Cooper shot back.

Cruz hammered down on his criticism of the cable-news networks that have aggressively covered Trump.

"Let's be clear: How many hours of free media does CNN and Fox and every other station [give him]? You let him call in and for a year, he got $2 billion in free media," Cruz said.

"We've asked you for interviews pretty much every day. And you've declined every offer on my program. So you can come on anytime," Cooper interjected.

But Cruz wouldn't budge. He pivoted to his call for Trump to debate him one-on-one and said that the real-estate mogul was "terrified" to face him again on a debate stage.

Cruz spent much of last year painstakingly refusing to criticize Trump, but that détente melted in the weeks leading up to the February 1 Iowa caucuses. With only three candidates left in the race, Cruz is now backed by much of the anti-Trump Republican establishment.

The two have exchanged fierce blows on almost every campaign-trail topic in recent days.

Over the past week, Cruz has repeatedly criticized Trump over the mogul's decision to retweet a photo critiquing Cruz's wife Heidi Cruz's physical appearance, among other issues.