Republican presidential front-runner Donald Trump said on Sunday that he's the one responsible for the surge in polls for 2016 Democratic hopeful Bernie Sanders against front-runner Hillary Clinton. During a rally in Muscatine, Iowa, Trump said that the Vermont senator only rose in the polls after he attacked former president Bill Clinton for his indiscretions. 

"Look, I was the best thing that ever happened to Bernie Sanders, because my attack on Hillary - all of a sudden she went down, and Sanders got all the credit for it, right?" Trump said at the rally, according to The Hill. "And then they start saying, 'Bernie Sanders is surging, an amazing thing happened.' I did it. I'm saying I did that."

Trump reiterated that Sanders, despite the large numbers of people who have shown up at his rallies since the beginning of his campaign, does not deserve credit for his success in the polls. "This guy Bernie Sanders - give me a break," said Trump. "How does he figure this whole thing? But he got all the credit - it's unbelievable."

On Sunday, appearing on NBC's Meet The Press, Sanders said in a face off, he would take down the real estate mogul. "There is nothing more in this world that I would like to take on more than Donald Trump," he said, according to NBC News. "We would beat him, and we would beat him badly." 

But Trump indicated he is keeping himself from returning the favor against Sanders because of the support it would offer the Clinton campaign.  

"I mean, here's a guy, he's a - well, they say socialist, but some people would say he's a communist, OK?" he said. "But I shouldn't hit him too hard, though, because if I hit him hard, he'll go down and then it'll be more of a fight with Hillary, and maybe we won't have to fight for a while. So I'll say, 'Isn't he a wonderful guy?'"

However, Trump warned that he has plans for Sanders, according to Bloomberg. "So now maybe I should hit - oh I could hit him," he said. "I have stuff in my mind. I could hit him so hard he would drop. He would drop. No, he's - he's - no, he's too easy. He's too easy. He's really too easy."