WASHINGTON, DC, United States (AFP) — Is it exhaustion, frustration, or a winning election strategy? The final weeks of Donald Trump’s campaign for the White House have been marked by a sharp rise in his use of vulgar language.

The brash billionaire has a long record of foul verbal outbursts, but his worst swearing and crudest asides have often been made privately. That’s changing.

This weekend, Trump was campaigning hard in the swing state of Pennsylvania, with barely two weeks to go until election day on November 5.

Rather than focus on his closing argument for why he should be president, he kicked off a rally with a story about late golf legend Arnold Palmer that crudely highlighted the size of Palmer’s penis.

“Arnold Palmer was all man,” Trump said with a laugh to the crowd of supporters.

“When he took showers with the other pros, they came out of there, they said ‘Oh, my God. That’s unbelievable’.”

“I had to say it!” he joked, leaving a CNN reporter spluttering during a live report from the scene.

When Trump moved onto politics, he kept it profane, using swear words to attack his Democratic opponent Kamala Harris.

“You’re a sh.. vice-president,” he said, delighting his cheering supporters.

Trump’s locker-room talk and cursing is popular with his audiences – and he may hope it reinforces his claim to be “man of the people” as he chases young voters.

The trend was evident in a podcast broadcast last week.

“I was so amazed that Harvey Weinstein got schlonged,” Trump said, using a term for male genitals while discussing the former movie producer who is in jail on rape charges.

And when Trump’s microphone stopped working at the recent rally in Michigan, he raged “I won’t pay the bill for this stupid company that rented us this crap” — again drawing wild applause.

Trump has also stepped up his regular insults such as “scum” to refer to anyone from migrants to unsupportive movie producers, as he faces a close election race with Harris — vying to become the first female US president.

She has certainly triggered a slew of Trump’s abusive language. He has called her “mentally impaired”, “retarded,” “a wack job” and “dumb as a rock”.

In August, Trump reposted a lewd social media remark referencing a sex act, as an apparent comment on Harris’s brief relationship with the then San Francisco mayor over 20 years ago.

Accusations that Trump, 78, is tired and angry on the campaign trail riled him to attack her again.

“I’ve gone 48 days now without a rest and I’ve got that loser who doesn’t have the energy of a rabbit,” he said.

Trump has benefited from his withering nicknames such as “Sleepy” Joe Biden, and he has shown that he can thrive by using vulgar, racist or misogynistic language.

Shortly before his 2016 election victory, audio tape emerged in which Trump said: “When you’re a star, they let you do it. You can do anything.”

“Grab ‘em by the pu..y. You can do anything.”

Trump’s latest cussing may leave his supporters – and many other Americans – neither shocked nor surprised.

But Harris hopes to turn the tables by painting him as unfit for office.

“I do believe that Donald Trump is an unserious man,” she said on Friday. “And the consequences of him ever getting back into the White House are brutally serious.”