A staggering number of Donald Trump's supporters are buying into one of his most unsettling theories

A staggering portion of Donald Trump's supporters are buying into his theory that the November election will be rigged, a Tuesday poll from Public Policy Polling showed.

The poll of North Carolina voters, which showed Democratic nominee Hillary Clinton up by 1 point, found that 69% of Trump's supporters think that if Clinton wins the election it will be because it was rigged. Just 16% think it will be because she got more votes than Trump.

Among all of those surveyed in the poll, 51% said that if Clinton wins the election it will be because she won more votes, while 36% said it will be the result of a rigged election. The remaining 13% were unsure if a Clinton victory would be the result of election rigging.

Last week, Trump began to hint at the defense for a potential loss this fall.

"And I'm telling you, November 8, we'd better be careful, because that election is going to be rigged," the New York billionaire told Fox News host Sean Hannity in one such example. "And I hope the Republicans are watching closely or it's going to be taken away from us."

Multiple Republicans told Business Insider Trump's assertion was both ludicrous and dangerous, as Trump would be the first presidential candidate in modern times, possibly ever, to blame an election loss on voter fraud or a rigged election.

Allen Raymond, a former GOP operative who was involved in the 2002 New Hampshire Senate election phone-jamming scandal, called Trump's continued insistence that the election will be rigged "detrimental to the Republic."

"We're not playing games anymore," he said. "This is far worse than, you remember that [Senate Majority Leader Mitch] McConnell quote about limiting [President Barack] Obama to one term? This is far more than that."

"The idea that it's rigged, I don't know what he's talking about," he continued. "I know someone that rigged elections. I mean, you know, the fact of the matter is Hillary Clinton doesn't need to rig this election. Trump's going to win Alabama and that's it. She doesn't have to do anything. It's painful to watch."

The Manhattan billionaire claimed to The Washington Post that a lack of voter-ID laws will let people "just keep voting and voting and voting" and accusations that fraud occurred in 2012 against Republican nominee Mitt Romney because there were "precincts where there were practically nobody voting for the Republican."

"I don't even know what he's talking about," Raymond said. "But this idea that it's 1950 or 1960 and the party bosses are going to roll into Pittsburgh and Philadelphia and are going to rig the ballot box and rig the machines - that's nonsense. An election rigging these days means something totally different than what he's talking about. Now it's stupid stuff like what I did in New Hampshire."

Matt Mackowiak, the founder and president of the Potomac Strategy Group repeated one word on a number of occassions to Business Insider in an attempt to describe Trump's "rigged" accusations: dangerous.

"And I don't even know if he realizes how dangerous it is," he said. "And, you know, we've got to have a peaceful transfer of power on November 8 no matter what the choice is. And this just raises the possibility that we won't. That's a really, really, really dangerous situation."