Donald Trump’s macho appeal that he alone can keep Americans safe and prosperous just isn’t working with white women — including many Republicans, a critical voting bloc this fall that is turning away from the Republican presidential nominee in numbers unseen in modern political memory.

Political operatives say they see evidence of the slippage on the ground, and polling confirms the shift as many women rebel against the style and substance of the billionaire businessman.

It’s a vulnerability the campaign says it’s aware of and is convinced it can solve, if Mr. Trump tailors his appeal correctly.

“We talk to a lot of security moms and security non-moms,” newly installed Trump campaign manager Kellyanne Conway said Thursday on CNN. “I’m very focused on non-moms, which is a growing group in our country — people who choose not to be married and choose not to have children. They’re very concerned about security — economic security, health security and certainly national security.”

That is what the Trump campaign has been counting on all along, but so far the candidate’s appeal — including his insistence that he is the only one who can break through Washington gridlock to get the economy moving and take on terrorists — isn’t gaining traction.

Geoffrey Skelley, associate editor of the political forecasting newsletter “Larry J. Sabato’s Crystal Ball,” said the security case is worth making, but women may be tuning out Mr. Trump as Democratic rival Hillary Clinton and her surrogates highlight what they say is his long history of misogynistic comments and questionable behavior.

“He’s already sort of dug himself a hole,” Mr. Skelley said. “It’s one of those things where some of these voters — they may just not be interested in listening at this point because they’ve already formed such a strong opinion of him.”

Barbara Norrander, a government and public policy professor at the University of Arizona, said the public has had plenty of time to get acquainted with the personalities and traits of the candidates, so policy-specific pitches are tough to get through.

“It’s pretty hard to change an opinion once it’s been out there for a while,” she said.

It’s so bad that a national Monmouth University poll shows Mr. Trump trailing Mrs. Clinton among white women with college degrees by a staggering 30 points. The 2012 Republican presidential nominee, Mitt Romney, won that group by 6 points.

“We are in an election where the gender gap could be bigger than it has ever been,” said Kathleen Dolan, a political science professor at the University of Wisconsin-Milwaukee.

Ms. Dolan, who studies election behavior and women in politics, cautioned against examining the election through a blanket “gender gap,” saying other divergences in the polling numbers involving race, religion, and economic and marital status are often bigger.

“I think that part of the problem he’s having with women is much more around his personality and who he is and his presentation,” she said. “He is obviously turning off large swaths of the country. I mean, this is not just a woman’s thing.”

Brad Crone, a Democratic strategist in North Carolina, said he has never before seen the level of Republican crossover as the rates in the Tar Heel State, a key battleground in November where Republicans have historically done well but where Mrs. Clinton has opened a lead in polls.

“You have white flight of Republican white women just leaving Trump rapidly, to the tune of 14 percent average statewide,” Mr. Crone said. “The last time that I saw that was in 1996 when Dole ran against Clinton, and that was a 6 percent crossover rate.”

Some polls show Mr. Trump not just underperforming among white women compared with past Republican nominees, but trailing Mrs. Clinton outright.

A Quinnipiac University poll on Iowa released this week showed Mrs. Clinton leading among white women by a 15-point margin, while Mr. Trump led among white men by 17 points. Mrs. Clinton held a narrow 3-point edge overall.

Another recent Quinnipiac poll on Pennsylvania told a similar story, with Mrs. Clinton leading by 11 points among white women en route to a 10-point overall lead. In a recent poll in Ohio, Mr. Trump held a 2-point lead among white women, but Mrs. Clinton led by 4 points overall.

“Given the outcomes in recent elections and what the exit polls show, Trump is doing very poorly compared to most Republicans,” Mr. Skelley said.

Ms. Norrander also said something that legitimately shifts the race’s overall trajectory is likely to involve both sexes anyway.

“If you wanted to change the gender gap, you’d have to have a message that resonates with one sex over the other,” she said. “If something’s going to change the general trend in the race, I think it would have more of an effect on both sexes.”

Still, the elevation of Ms. Conway, a veteran Republican pollster who has worked on tailoring conservative messaging toward women, could help change the image of a Trump campaign that is often seen as a boys’ club.

“Much of her work with her clients is about trying to get them to speak in a language that women don’t find repugnant,” Ms. Dolan said of Ms. Conway.

But Ms. Dolan also said segmentations into “soccer moms,” “security moms” and even “NASCAR dads” oversimplify voter blocs, and she isn’t sure Mr. Trump can pull his campaign together to get his message across anyway.

“There isn’t a segment of security moms out there,” she said. “There are women of every color and size and shape and life situation, and they’re really not necessarily easily categorized.”

Sign up for Daily Newsletters Manage Newsletters

Copyright © 2020 The Washington Times, LLC. Click here for reprint permission.