Trump is entitled to his opinion and he does have evidence to back it up. I know its unpopular to talk about but the truth is that the media has not been impartial and now it appears that O'Keefe has video evidence of the dems posing as violent trump supporters. If that turns out to be true than it takes the thunder out of the OP, no?
I watched most of the video and what it purports to show (with O'Keefe, who knows since he has a long history of dishonest editing) are democratic shills put in the crowds to bait Trump supporters into violent reactions to them. They're posing (if anything) as liberals.
And, no, he has no evidence, NONE, zilch, nada, nothing indicating a rigged vote, or a rigged election. Or, if he has it, make it public, be specific, explain his concerns in detail, down to the state, county precinct. Otherwise, reckless and baseless charges have no business coming out of the mouth of a POTUS nominee. That's what the old Trump, the celebrity actor, could do - now he wants a different job in which what he says matters, all over the globe.
Nor does he have a reasonable expectation of what he'd consider "unbiased" reporting on his campaign. You can complain, boycott, whatever whoever you want in the so-called MSM who you don't think have been fair, but the "press" has a long, long, long history of taking sides in political campaigns - Fox News does it every day, so does Rush, Hannity, Levine, Savage, NRO, Heritage Foundation, Breitbart.com, et al. It's the job of the candidate to get the press behind him, not the duty of the press to report on a nutcase with perfect impartiality and objectivity.