Newt Gingrich said Donald Trump would be beating Hillary Clinton by 15 points if the media wasn't lined up against his candidacy during an interview Sunday on ABC's This Week.

A new four-way NBC News poll shows Clinton leading Trump by 11 points, while an ABC News poll showed a tighter race with Clinton leading by four points.

Trump spoke this week about the election potentially being "rigged," and he also ripped the media for unfairly helping his Democratic opponent. Sen. Jeff Sessions (R., Ala.) said this week, "they are attempting to rig this election."

"Who are ‘they,' and how are they doing this?" host Martha Raddatz asked.

"Well, I think ‘they' are the news media," Gingrich said. "This is not about election officials at the precinct level. This is about last Friday when the networks spent 23 minutes on the Trump tape and less than one minute—all three networks combined—less than one minute on Hillary Clinton's secret speeches that were being revealed in WikiLeaks."

Gingrich said it was "amazing" that Trump was within striking distance of Clinton in the polls with that kind of disparity. He also defended Trump's call for poll watchers.

"I'm old enough. I remember when Richard Nixon had the election stolen [by John F. Kennedy] in 1960, and no serious historian doubts that Illinois and Texas were stolen," he said.

"So you really think this election could be stolen," Raddatz said. "Do you believe that if Mr. Trump loses, it will be because of a massive conspiracy or fraud, not because more Americans voted for somebody else?"

"I think that without the unending, one-sided assault of the news media, Trump would be beating Hillary by 15 points," Gingrich said. "I think when you look at WikiLeaks and you look at all the things she has said, when you look at the deals in Russia that Bill Clinton made, and that the Clinton Foundation made … The news media's one-sidedness is the worst I've seen in my lifetime, and I'm old enough. That's a fairly long statement."

Gingrich has been a longtime Trump supporter but has also criticized him publicly. This week, after a torrent of sexual abuse allegations against Trump that he denied, Gingrich mentioned there is a "big Trump and a "little Trump" and the latter is "frankly pathetic."