Well, this is awkward.
The head-turning assertion came in a Washington Post article in which Rendell was quoted assessing Trump's chances of carrying Pennsylvania, won by the Democratic presidential candidate in every election since Bill Clinton's victory in 1992.
"Will he have some appeal to working-class Dems in Levittown or Bristol? Sure," Rendell was quoted as saying. "For every one, he'll lose 1½, two Republican women. Trump's comments like `You can't be a 10 if you're flat-chested,' that'll come back to haunt him. There are probably more ugly women in America than attractive women. People take that stuff personally."
The remark went viral and put Democratic Senate nominee Katie McGinty in a ticklish spot. Rendell is chairman of McGinty's campaign.
"Gov. Rendell's comments were completely off-base and inappropriate," said Sabrina Singh, McGinty's spokeswoman. She said the candidate was not available for comment.
By the end of the day, Rendell was delivering a mea culpa to reporters. "It was dumb and insensitive and stupid, and if I offended anybody, I apologize," he said Wednesday night.
Philadelphia City Councilwoman Maria A. Quiñones-Sánchez took a more humorous approach.
"I think women will vote on substance," she said. "They won't be for Trump, but it won't be because he's barely a `3.' "
Rendell also is a vocal supporter of Hillary Clinton, who could become the first female president. When asked for comment, her campaign said it agreed with Rendell's apology.
Gov. Wolf was not amused.
"The former governor's comments are unfortunate and offensive, and the governor disagrees with them," said Jeff Sheridan, Wolf's spokesman.
Asked whether Wolf believed there was such a thing as an "ugly woman" vote, Sheridan said, "No."
After eight years as Philadelphia's mayor, Rendell built his two statewide victories on the formula that has boosted the party's presidential nominees in the last six elections: overwhelming margins of support in the city and its suburbs to offset outstate opposition. He also has a record of appointing women to important positions in his governments in both the city and the capital.
And he has an extensive history of verbal blunders, including some that were viewed as sexist.
In 2008, an open microphone caught him praising the choice of then-Arizona Gov. Janet Napolitano as homeland security secretary because she had "no life" and "no family," and could devote nearly every waking hour to work.
Chuck Ardo, who was Rendell's spokesman when he was governor, said people who have worked with him know he is sometimes apt to "shoot off at the lip."
Those acquainted with his career might shrug at the "ugly women" comments. "But," Ardo said, "I would bet you dollars to doughnuts they make the Clinton camp cringe."
Even so, Ardo said, he doesn't believe Rendell meant to offend.
"I have always known Ed Rendell to have great respect for women," Ardo said. "I have also always known that he has a tendency to say things badly at times. I am confident his intent was pure."
Staff writer Claudia Vargas contributed to this article.
Some previous gaffes from the former Philadelphia mayor and Pennsylvania governor:
"Rosita, that red dress you've got on. ... Do you have any green panties with it?"
Democratic ward leader Betty Townes quoted then-Mayor Ed Rendell as saying this to State Rep. Rosita Youngblood at a holiday party in 1992. Rendell's chief aide at the time, David L. Cohen, said that no offense was meant and that the mayor sent an apology.
"Take it off, Lis! Take everything off! ... Lis must have a spiked metal bra on or something, 'cause we almost didn't get in."
Philadelphia Magazine writer Lisa DePaulo quoted Rendell in 1994 as saying this as she went through a metal detector. She also wrote that during a limousine ride, Rendell told her, "in raw and alliterative terms, how he presumes I am in bed. All of which he says I `should find flattering.' " Rendell later said he meant no offense and "100 percent of this was kidding."
Rendell, who is Jewish, said in August 2000 when he was general chairman of the Democratic National Committee that if Connecticut Sen. Joseph I. Lieberman were Episcopalian and not Jewish, his selection as Al Gore's running mate would be a "slam dunk." Days later, Gore put Lieberman in the ticket.
"Janet has no family. Perfect. She can devote, literally, 19, 20 hours a day to it."
Rendell's commen on Arizona Gov. Janet Napolitano's being nominated as secretary of homeland security in December 2008. Rendell later said his words, caught on an open microphone, merely meant that he and she, like other governors, worked long hours and had "no life."