Bill O'Reilly says Republican candidates have to 'stop whining' about debates

The line from Republican presidential hopefuls since the CNBC debate last week has been that the moderators were too negative.

Marco Rubio called the questions "irritating," and Ted Cruz likened the event to a "cage match."

Fox News' Bill O'Reilly echoed those complaints when he was on Jimmy Fallon's Tonight Show Tuesday night, saying "you can be tough" but the debate crossed a line into "openly hostile." The debate's style was a "mistake" for the network, he said.

But O'Reilly also had some tough feedback for the candidates. "These guys gotta stop whining," he said. "You got a microphone, let 'em have it. That's why Trump is ahead in the polls. Because he just says what he wants to say and he takes on all comers, and the folks want to see what you're made out of."

O'Reilly also had some "demands" for future debates, and enlisted the comedy styling of Fallon to help him demonstrate them. Watch below: