Donald Trump preemptively challenged the results of the November presidential election, claiming in media appearances and rallies that the entire system is “rigged.” Trump’s charges of election fraud are not new to his campaign. He’s 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. … This is a serious allegation that challenges the integrity of the election, so we asked the Trump campaign to elaborate. We didn’t hear back. When Trump has offered specifics — people voting though they’re ineligible, people voting multiple times, people impersonating dead voters — he’s actually talking about voter fraud, committed by individuals and committed very rarely. … Trump suggested this in 2012 when hewarned that machines were switching Romney votes to Obama. “That’s not an indication of the system being rigged. That’s an indication that it’s lost its calibration,” said Pamela Smith of Verified Voting, which monitors technological issues in elections.
She added that Trump likely was referring to voter reports of this common issue of overuse, while election rigging “would require you not noticing.” (Smith couldn’t think of any examples of machines being tampered with and said, from her research, issues usually result from programming errors.)
Ballots cast on some electronic voting systems, however, don’t have a paper trail, meaning the votes are not verifiable. Hackers could theoretically alter the results. But this would also require a potential wrongdoer to physically access the machines on Election Day and serious coordination to circumvent all the security and auditing measures in place before, during and after voting, said Smith, adding, “There are very few paths in the present scenario to flip something off the radar.”
… While there are isolated examples of bought local elections, experts say it cannot be replicated on a national scale. While it is possible to tamper with electronic voting machines, there is no evidence deliberate malfeasance has altered any election. We rate Trump’s claim Pants on Fire.