Philadelphia attracts attention for its place in a swing state. It was where a 2008 news article about two New Black Panthers patrolling a polling place gained mythic proportions. And the city — once home to a mighty Republican political machine — does have a history of corrupt elections dating to the 1970s-era mayor Frank Rizzo.
But the most evocative evidence among conspiracy theorists about Philadelphia today turns on a single data point about the 2012 election. There were 59 voting divisions, or precincts, in the city where President Obama swept 100 percent of the vote. The Republican nominee, Mitt Romney, swayed not one soul in these places. A few conservative pundits have called the pattern statistically impossible. Mr. Trump himself has been incredulous: “I mean, like no votes.”
There is another, more credible, explanation. “This is definitely more about math than fraud,” said Jeffrey Carroll, an assistant professor of political science at Chestnut Hill College in Philadelphia who has analyzed those 2012 results. It is math partly of the G.O.P.’s own making.
In fact, there are predominantly black pockets in Philadelphia where no one wanted to vote for Mr. Romney. (Officials including the city’s Republican commissioner have looked at the data and today’s hard-to-rig voting machines and concluded the same).