His White House campaign in chaos over snowballing accusations of sexual assault, Trump has cast himself as the victim of a "smear campaign," further escalating his attacks in a scorched-earth strategy heading into the final weeks of the race.
"Hillary is running for president in what looks like a rigged election," the 70-year-old told a fired-up rally in Portsmouth, New Hampshire. "The election is being rigged by corrupt media pushing completely false allegations and outright lies in an effort to elect her president."
Trump tweeted out a similar allegation earlier Saturday to his 12 million followers, charging: "Hillary Clinton should have been prosecuted and should be in jail. Instead she is running for president in what looks like a rigged election."
In a bizarre new attack on the Democratic nominee, he suggested she had taken performance-enhancing drugs during their last debate.
He called for her to be screened ahead of their final televised duel Wednesday in Las Vegas.
"I don't know what is going on with her. At the beginning of her last debate, she was all pumped up at the beginning. At the end, it was like, take me down, she could barely reach her car."
"Athletes, they make them take a drug test. I think we should take a drug test prior to the debate. Why don't we do that?"
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As the Manhattan billionaire tanks in the polls, he has spent the last week claiming the media and a "global elite" is working against him, and that Clinton had plotted to destroy the sovereignty of the United States.
"Either we win this election or we lose this country," he told supporters in New Hampshire.
"I really believe this is the last chance we have to win. I really believe it. Not going to happen again."
The Clinton camp issued an immediate response, accusing Trump of seeking to erode public faith in the November 8 vote.
"Campaigns should be hard-fought and elections hard-won, but what is fundamental about the American electoral system is that it is free, fair and open to the people," her campaign manager Robby Mook said in a statement.
"This election will have record turnout, because voters see through Donald Trump's shameful attempts to undermine an election weeks before it happens."
The virulence of Trump's attacks on the Clinton camp have raised concerns about whether the real estate mogul would even acknowledge a defeat, and how his legions of fired-up supporters would react should he lose.
President Barack Obama echoed those concerns at a campaign rally Friday.
"This is somebody who... is now suggesting that if the election doesn't go his way, it's not because of all the stuff he's said, but it's because it's rigged and it's a fraud," Obama said.
"You don't start complaining about the refs before the game's even done. You just play the game, right?"
