Story highlights "I'm telling you, November 8, we'd better be careful, because that election is going to be rigged," Trump says

Columbus, Ohio (CNN) Donald Trump on Monday took his complaints about the "rigged" political system one step further.

"I'm afraid the election's going to be rigged. I have to be honest," Trump told voters in Ohio, a crucial swing state.

Trump's comments Monday came as he decried Vermont Sen. Bernie Sanders for endorsing Hillary Clinton in the Democratic primary, even as some Sanders supporters have continued to resist unifying behind the nominee. Trump has sought to siphon off Sanders supporters and draw them to his campaign.

Trump added that he has heard "more and more" that the November election will be rigged -- suggesting to his supporters that the outcome of the election is out of the hands of voters.

Hillary Clinton's spokesman Brian Fallon mocked Trump on Twitter Tuesday morning, writing, "Even for a reflexive conspiracy theorist like Trump, this is pathetic. It's dangerous, too."

Even for a reflexive conspiracy theorist like Trump, this is pathetic. It's dangerous, too.https://t.co/hcd4kQ4VS9 — Brian Fallon (@brianefallon) August 2, 2016

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