WASHINGTON — Donald Trump will not change.

He may surround himself with new staff and even listen to their advice for a while. He may stick to a scripted, more measured message if it looks to be working.

But he’ll always be the man who can’t let go of a grudge, whether it’s with a judge who ruled against him or a military father whose son was killed fighting for the United States overseas.

He’ll always be the man who embarrassed a young beauty queen about her weight, then defended his comments two decades later when Hillary Clinton raised them in a debate. And the man who on Friday — just 38 days away from potentially being elected president of the United States — deepened his highly personal criticism of former Miss Universe Alicia Machado in a pre-dawn Twitter tirade.

“Did Crooked Hillary help disgusting (check out sex tape and past) Alicia M become a U.S. citizen so she could use her in the debate?” Trump wrote in a message timestamped 5:30 a.m.

Some voters may applaud Trump’s moves. Some may prefer his stubborn refusal to censor himself. Enough voters may ultimately elect him president.

But Trump’s pattern of abrasive behavior has left him deeply unpopular with many Americans, particularly women and minorities, who hold significant sway in presidential elections. If Trump does win in November, he’ll have to figure out a way to lead a country where many people believe he’s racist, sexist and uncivil.

Most Republican leaders long ago gave up hope that Trump would make a full-scale pivot into a more palatable politician in the general election. But they’ve still found ways to rationalize their support for him, to look past his most volatile moments and offensive rhetoric.

Some Republicans hinge their hopes on a belief that if Trump is elected president, he’ll surround himself with high-quality experts to help guide his decision-making. House Speaker Paul Ryan and Texas Sen. Ted Cruz, both of whom have their own designs on the White House, argue a Trump presidency would at least give them a chance of implementing conservative legislation in Congress, while a Clinton White House would be nothing more than an impenetrable roadblock.

But Republicans might also worry that Clinton’s ability to get under Trump’s skin so easily has provided a blueprint that world leaders like Russia’s Vladimir Putin could use to rile him as president. And they should have no illusions that the brash businessman can control his belligerent behavior and avoid offending many Americans.

Trump’s decades in the public eye are littered with examples of long-held grudges with business associates and demeaning comments about women. One of his first moves after clinching the Republican nomination was to start a feud with U.S. District Court Judge Gonzalo Curiel, claiming his Mexican heritage made him biased against Trump in a legal case. Trump emerged from the party conventions this summer locked in an ugly fight with Khizr Khan, an American Muslim whose son was killed serving the U.S. Army in Iraq.

The latest controversy came at one of the most critical stages of the campaign — on the debate stage in front of a televised audience of 84 million people and with early voting already underway in some states.

Trump struggled in Monday night’s debate to fend off Clinton’s criticism of comments he made about Machado two decades earlier. When Clinton accused him of calling the former Miss Universe “Miss Piggy,” he said, “Where did you find this? Where did you find this?”

Rather than let the matter go, he defended himself the next morning, apparently blind to how offensive his comments seemed.

“She gained a massive amount of weight,” said Trump, who owned the pageant at the time she won. “It was a real problem. We had a real problem.”

Surely by week’s end, Trump was aware that his criticism of Machado risked damaging his campaign and giving Clinton fresh fodder to argue that he is too thin-skinned to serve as commander in chief.

That made his decision to keep the story alive Friday and deepen his denigration of Machado all the more perplexing.

“Using Alicia M in the debate as a paragon of virtue just shows that Crooked Hillary suffers from BAD JUDGEMENT! Hillary was set up by a con,” Trump wrote in one of three early morning messages about the Venezuelan-born Machado, who is now an American citizen.

Clinton advisers can hardly believe their good fortune as the race barrels toward the finish line. The Democrat has been dragged down by decades of her own baggage and has struggled to persuade voters she is honest and trustworthy. And the race with Trump is far closer than most Clinton supporters expected.

But the core of Clinton’s case against Trump has always been that the Republican is too hypersensitive to be trusted in the Oval Office. And just over five weeks from Election Day, Trump is giving her more evidence.

“When something gets under Donald’s thin skin, he lashes out and can’t let go,” Clinton wrote in her own Twitter message Friday. “This is dangerous for a president.”

Julie Pace has covered the White House and politics for The Associated Press since 2007. Follow her at http://twitter.com/jpaceDC

AP News Analysis