Donald Trump tripled down on his baseless claim that the U.S. election system is rigged against him, capping a weekend of lashing out at the media for publishing "fabricated" allegations of sexual assault and at Alec Baldwin for impersonating Trump on Saturday Night Live.

House Speaker Paul Ryan and other Republicans defended the Election Day process at an Oct. 15 rally, but Trump continued to blame the media for "pushing Crooked Hillary" and added that rigging is happening at "many polling places."

"Of course there is large scale voter fraud happening on and before election day. Why do Republican leaders deny what is going on? So naive!" Trump tweeted the morning of Oct. 17.

Of course there is large scale voter fraud happening on and before election day. Why do Republican leaders deny what is going on? So naive! — Donald J. Trump (@realDonaldTrump) October 17, 2016

The Trump campaign reiterated Trump’s stance that the cards are stacked against Trump, pointing to a column from The Hill's media reporter Joe Concha on how the media could influence voter perceptions of Trump. To be clear, this is not the same thing as a voter committing fraud.

The Trump campaign also pointed us to a 2012 Pew Center study that estimated about 24 million, equal to one in every eight, voter registrations in the United States are no longer valid or are inaccurate. But as we have previously reported, no evidence of voter fraud was found — this is about record-keeping that is badly managed and in disarray.

The other piece of evidence offered by the Trump campaign is a 2014 study that says approximately 6.4 percent of noncitizens voted in 2008 and 2.2 percent in 2010. That study has been criticized by election experts for using an unreliable database of Internet respondents.

And finally, the Trump campaign forwarded us reports of voting irregularities in swing states like Pennsylvania, Colorado and Virginia. But these reports were either of reported and prevented cases of fraud or isolated instances. They do not amount to rampant, widespread fraud or assert that the few cases affected the outcome of an election.

Voter fraud is rare. Trump talking about it is not.

Voter fraud isn’t a catch-all term for any election shenanigan. Voter fraud is rare and refers to illegal interference in voting, such as ballot stuffing, voter impersonation or vote buying.

Before his White House bid, Trump tweeted about dead voters delivering President Barack Obama’s victory in 2012, floated charges about multiple voting in the primaries, and suggested that undocumented immigrants "just walk in and vote" in some polling places.

These charges do not reflect reality.

News 21, a national investigative reporting project funded by the Carnegie Corporation of New York and the John S. and James L. Knight Foundation, found 150 alleged cases of double voting, 56 cases of noncitizens voting, and 10 cases of voter impersonation across all elections from 2000 to 2011. Many of these allegations never led to charges, while others were acquitted or dismissed.

Justin Levitt, a professor at Loyola Law School and an expert on voter fraud, found an even smaller number: 31 credible incidents out of more than 1 billion votes cast from 2000 to 2014.

Put it in another way: More people are struck by lightning or attacked by sharks than are accused of voter fraud.

When voter fraud does occur, it’s not always intentional. Multiple studies have traced known cases not to willful deception but to clerical errors or confusion.

For example, one case of a dead person voting (Alan J. Mandell) happened because a poll worker accidentally marked his name instead of the man who actually cast the ballot, Alan J. Mandel. Similarly, in one of just five cases of a noncitizen voting between 2000 and 2004, a permanent resident was told he was eligible and given a voter registration form by a DMV clerk when renewing his license.

So, given the rarity of occurrence, the lack of intent, and a federal penalty of a $10,000 fine or up to five years in prison, experts say it would be extremely difficult to rig an election through the ways Trump has decried.

"I'd like to see him try to vote 10 times on Election Day. It would be virtually impossible and a knuckle-headed way to try to corrupt an election," Lorraine Minnite, a political science professor at Rutgers University who wrote The Myth of Voter Fraud, previously told PolitiFact.

For double or triple voting to sway an election, an army of voters would have to visit multiple polling locations each, know the names and addresses of the people they were impersonating and produce fake IDs (in many states) or forge their signatures — plus commit to committing perjury the entire time.

"Campaigns don’t pay people to pretend to be people they’re not. That’s too stupid," said Mary Frances Berry, former chairwoman of the U.S Commission on Civil Rights and author of Five Dollars and a Pork Chop Sandwich, a book about electoral fraud.

So there is no evidence of a massive attempt to rig the election on and before Election Day.

Collusion confusion

Trump elaborated on his voter fraud theory a few hours after his initial tweet.

"Voter fraud! Crooked Hillary Clinton even got the questions to a debate, and nobody says a word. Can you imagine if I got the questions?" he tweeted.

His follow-up is not evidence of large-scale voter fraud, though it does bring up a separate concern revealed by Wikileaks.

Trump is referring to an email obtained by Wikileaks from then-CNN contributor and Democratic strategist Donna Brazile with the subject line, "From time to time, I get the the questions in advance."

"Here’s one that worries me about HRC," Brazile wrote to Clinton’s communications director Jennifer Palmieri on March 12, 2016. "Should Ohio and the 30 other states join the current list and abolish the death penalty?"

Palmieri wrote back: "Hi. Yes, it is one she gets asked about. Not everyone likes her answer but can share it."

The next day, CNN co-moderated a Democratic primary town hall, and one person asked Clinton about the death penalty.

But Brazile, who is now interim Democratic National Committee chairwoman, has denied that she notified the Clinton camp of the question and says she never had access to the questions in the first place. (The Clinton campaign has yet to confirm or deny the authenticity of the emails.)

A CNN spokesperson told Politico, "we have never, ever given a town hall question to anyone beforehand." CNN host Jake Tapper, one of the debate moderators, called the leak "very, very upsetting," and the network has blamed debate partner TV One as the source.

This is concerning, but none of it is evidence of voter fraud.

Our ruling

Trump said, "Of course, there is large scale voter fraud happening on and before election day."

Actual instances of voter fraud — such as voter impersonation, ballot stuffing and bought votes — are extremely rare, often unintentional and not on a scale large enough to affect a national election. Trump's alarming claim, once again, is without proof.

We rate Trump’s claim Pants on Fire.

https://www.sharethefacts.co/share/43048df5-6484-4ff3-b329-62f96846cd82

Correction: A previous version of this story incorrectly characterized Joe Concha's current job title. He is a media reporter and columnist at The Hill.