David Thornburgh is the president and CEO of the Committee of Seventy.

PHILADELPHIA — Donald Trump and his campaign surrogates say they believe that a massive conspiracy will be operating in Pennsylvania to “steal this election” for Hillary Clinton on Nov. 8. Specifically, they’re worried about Philadelphia.

“We have to make sure the people of Philadelphia are protected that the vote counts are 100 percent,” Trump said last week in Wilkes-Barre, Pa. “Everybody wants that, but I hear these horror shows. I hear these horror shows and we have to make sure that this election is not stolen from us and is not taken away from us. And everybody knows what I’m talking about.” His ally Newt Gingrich was even blunter, saying that “to suggest that you don’t have theft in Philadelphia is to deny reality.” Rudy Giuliani predicted that people would be bused to Philadelphia to vote “four or five times” in place of dead voters on the rolls.

I’m the chief executive of the Committee of Seventy, a nonpartisan, nonprofit good-government organization in Philadelphia formed by private-sector leaders in 1904 with a primary mission to protect and improve the voting process. I’ve lived in Philadelphia for more than 30 years. I also happen to be a son of Dick Thornburgh, a former Republican governor of Pennsylvania and U.S. attorney general under Presidents Ronald Reagan and George H.W. Bush. (For the record, I’m a registered independent.)

So I know what I’m talking about when I say that Trump’s charges are preposterous. They have no basis in fact, and they are dangerous and damaging to our democracy.

Trump has offered no evidence to support his claims, and it’s hard to beat nothing with something. But even if it won’t persuade him, for the sake of the rest of the country, let me review the reality of voting in Philadelphia.

Like most big cities these days, Philadelphia has an overwhelmingly Democratic electorate, with about eight Democrats for every Republican. It does have an old-fashioned Democratic machine, but it’s pretty creaky. Yes, it still has enough muscle to elect local judges and row officers, and some state legislators, but, more important, it doesn’t need to steal votes to elect Democrats. Democrats win elections by margins here that are among the biggest in the country. In 2012, the 85.2 percent of Philadelphia voters who voted for President Obama was second only to the Bronx’s 91 percent. Philadelphia’s margin even beat Obama’s home town, Chicago, by a percentage point.

On the Trumpiest fringes of the Internet, that Obama margin in 2012 is taken as proof that the conspiracy is real. Four years ago, in 59 voting divisions (Philly-speak for precincts), Republican Mitt Romney won zero votes. But to anyone who knows anything about our city, that isn’t quite as sinister as it might appear. All 59 divisions are in heavily African American neighborhoods, where finding Republicans is hard even when the nation’s first black president isn’t on the ballot. In any event, those areas, each encompassing just a few city blocks, are only 3 percent of Philadelphia’s 1,686 voting divisions and accounted for only 19,605 of the 690,776 votes cast in the city. And those divisions weren’t exactly outliers: GOP candidates have won only 3 percent of the black vote citywide in recent elections; a July NBC/Wall Street Journal poll found no measurable African American support for Trump in all of Pennsylvania; and an August Fox News poll put Trump’s support among blacks at 1 percent nationwide. As Philadelphia GOP executive director Joe DeFelice told the Philadelphia Inquirer about the Romney shutouts: “I think it’s plausible. I understand the demographics of the area.”

Another Internet favorite is the two members of the New Black Panthers who were accused of menacing voters outside a Philly polling place in 2008. A visit to YouTube confirms their uncomfortable presence at the polls. But while the division they chose to menace — 14th ward, 4th division — did go 596 to 13 for Obama over Sen. John McCain, it wasn’t because Republicans were scared away. Most folks in the 4th division are African Americans, and registered Democrats currently outnumber registered Republicans in the 14th ward 5,040 to 276. Four years later, by the way, Obama carried the division 568 to 2 while amassing a 492,000-vote victory over Romney in Philadelphia.

The kind of fraud Trump claims will be going on here would be nearly impossible to pull off. (Voter fraud is virtually nonexistent nationwide, for the same reason.) As the veteran Philadelphia political journalist Tom Ferrick put it in an article on the news site City & State last week: “It would take a massive organizing effort and would yield minimal results.” Say you want to pay impostors to impersonate registered voters. In 2012, Romney would have needed at least 150,000 more votes than he got in Philadelphia to win Pennsylvania’s 20 electoral votes. Ferrick suggests a potential election thief would pay phony voters $20 each (a small reward for a potential felony charge, by the way), which means it would have cost Obama more than $3 million to come up with the winning margin. Could you possibly hide that much money AND also keep 150,000 fake voters quiet? Don’t let anyone try to confuse this scenario, by the way, with the long-standing Philadelphia tradition of party officials doling out “street money” ($100 or so and a hoagie for lunch) to partisan activists for their legal efforts to get their voters to the polls. One is criminal fraud, and one is paying people for a long day of work.

Could potential fraudsters monkey with voting machines? Actually, in Philadelphia, they are almost a decade and half old, they are not connected to the Internet, and they are constructed in a way that makes it impossible to remove votes from them once they are cast. We are literally protected by their obsolescence.

This is not to say that our election system works flawlessly. In fact, the Committee of Seventy has helped organize a Better Philly Elections coalition of a dozen civic groups to advocate for replacing the politicized and inefficient elected City Commissioners — who oversee voting here — with an appointed election professional and a nonpartisan board of elections.

But there’s a difference between fraud and mere incompetence. In 2012, Commissioner Al Schmidt, the lone Republican of the City Commissioners, took a sampling of all voters in the primary election. His study found infractions ranging from voting by people who weren’t registered — some of whom weren’t citizens — to, yes, voter impersonation. But there were very, very few of them. Only 19 noncitizens voted, in a city with more than 1.5 million residents. That November, massive confusion and mismanagement at the Election Board caused more than 12,000 registered voters to have to cast provisional ballots. But the inconvenienced voters were mostly Democrats; a Democrat trying to steal an election probably wouldn’t go out of his way to disenfranchise his own supporters.

Perhaps more seriously, in 2012, Democratic judges of election refused to seat about 100 Republican inspectors in their divisions. True, it would be hard to prove that none of these election judges had larceny in mind. But I’ve observed Philly elections long enough to know that many, many Republican inspector slots go unfilled because no actual Republicans seek them, and they must be filled instead by what are quaintly called “curbside elections” involving the parties, the Election Board and local courts. Not surprisingly, many of those posts then go to friends and relatives of the election judges — friends who will miss out on an Election Day payday ($100) if they’re unseated. Even seen in the most negative light possible, these infractions amount to petty fraud to get some friends a little cash, not wholesale conspiracy to affect the outcome of the election. They are buried by an avalanche of incompetence and just plain human error — and, again, they don’t add up to enough votes to make a difference in the result.

The real reason Philadelphia produces lopsided results in favor of Democrats is simple: There just aren’t enough Republicans there. To suggest otherwise, as Trump does, undermines the foundations of our democracy.

Read more:

No candidate in U.S. history has used the kind of ‘rigged’ rhetoric Trump is using

Courts are finally pointing out the racism behind voter ID laws

U.S. elections ranked worst among Western democracies. Here’s why.