The gloves have come off what was one of the more civil relationships in the soap opera that has been the Republican presidential nomination. process.

Donald Trump called fellow GOP candidate Sen. Ted Cruz (R-Texas), “a maniac” this past weekend and said that he was not “qualified to be president,” as polling suggests that support for Trump may be waning in Iowa.

"When you look at the way he's dealt with the Senate, where he goes in there, like a, you know, frankly like a little bit of a maniac, you're never going to get things done that way," Trump said of Cruz following the news the Texas senator had jumped in the polls.

According to a story from Bloomberg News,  its most recent poll shows Cruz has the support of 31 percent  of those likely to attend the Republican caucuses on Feb. 1, with Trump at 21 percent. Trump's numbers have grown since October despite, or because of, some of the more outrageous statements he's made since August. He was at a high of 23 percent support then.

The Real Clear Politics average of polls for Iowa put Cruz solidly in the lead there as of last week.

Throughout the election season, Cruz has been notably missing from Trump's public assessments of his competition, and the pair have been collegial opponents. However, since the release of an audio tape where a person identified as Cruz is heard knocking Trump at a fund-raising dinner, the two have been ramping up the rhetoric via social media.

"Both of them I like and respect,” Cruz said of Trump and fellow GOP candidate Ben Carson on the audio tape. “I don't believe either one of them is going to be our president.” Cruz was speaking before 70 people at an event in New York City.

Trump was quick to jump on the news of the audio tape.

Cruz responded:

"We have had a very good relationship," Trump told Fox News'  "Fox and Friends Weekend" on Saturday.   "I'm sure it will end because, you know, he has got to come after me at some point. I'm leading by a lot as you know, so at some point he is going to come after me but I like him and I think he likes me. And we have had some fun on the trail."

According to a Washington Post story, Cruz's leap in the polls can be linked directly to a months-long effort by his campaign to profile and target potential supporters. According to the story, Cruz's campaign has targeted Iowa Caucus-voters with a tailored messages, phone calls and visits using a method called "psychographic targeting."