Of all the insults hurled at Donald Trump, few have pierced that famously rhino hide of his. You can count on the fingers of one unnaturally small hand the remarks that have truly bothered him. Now a new barb is in play: weird.

Kamala Harris first tried it on Trump. Then her running mate, Tim Walz, applied it to JD “beware the childless cat ladies” Vance and it worked even better. Though some strategists question whether voters will get it, Harris and Walz have decided to go with the W-word, big time.

An aggrieved Trump told an interviewer that nobody had ever called him weird. “I’m a lot of things but weird I’m not,” he said. The word was still bugging him when he spoke at a rally in Montana. We’re not weird, he said of himself and Vance.

“We’re very solid people. We want to have strong borders, good elections, low interest rates, we want to be able to buy a house.”

At the same rally, Trump tried out an attack line that looks set to become a regular. Weirdly enough, it has links to the land his mother hailed from, Scotland.

As governor of Minnesota, Walz last year backed a law to put free period products in schools. As readers in these parts will know, the Scottish Parliament was the first in the world to pass such an act following years of campaigning by Labour MSP Monica Lennon. If Mr Trump knew of the idea’s history he did not say.

Mention of the Walz scheme, which includes making provision for transgender boys, was met with booing from the crowd. “Do we have any children here? Please close your ears,” said Trump.

The Montana rally followed a Trump press conference at his Mar-a-Lago resort that is still making headlines for all the wrong reasons. First, he falsely claimed the crowd at his January 6 speech was bigger than the one that heard Martin Luther King’s “I Have a Dream”.

Then he claimed to have narrowly escaped a helicopter crash while travelling with Willie Brown, the former mayor of San Francisco who has been in the news because he and Harris dated in the mid-1990s. “We thought, maybe this is the end,” said Trump of the 2018 trip. Brown, however, said he had never been anywhere near a helicopter with Trump.

According to one former aide, the hastily arranged press conference at Mar-a-Lago was a sign Trump was panicking. “He hates the coverage Harris is getting and thinks only he can fix it,” said Stephanie Grisham on X/Twitter.

Summer has not turned out as well as Team Trump thought it would. The JD Vance pick raised eyebrows among senior Republicans, while the speed of Biden’s departure and Harris taking over took Trump by surprise. Harris added to the feel-good factor around her by choosing Walz, an affable, Steve Martin-lookalike for a running mate.

After so long spent with the same story of Biden being too old and frail, suddenly journalists had lots of new faces to focus on.

In what some might see as karma, the campaign tables have turned and it is now Trump’s age that is being questioned. Transport secretary Pete Buttigieg told CNN the 78-year-old had “lost his step” and was becoming “mushier, fuzzier, more confused”.

To quote a British political saying, he would say that, wouldn’t he? By way of a fightback, Trump has announced a sit-down with his new number one fan, Elon Musk, to be streamed live on X this week.

The attention won’t stray from Harris for long. The Democrats have their convention/coronation in Chicago in mid-August, with more primetime coverage guaranteed, night after night.

Then comes the biggest bunfight of all - the first Trump-Harris live televised debate on September 10. Trump-Biden in June, which turned out disastrously for the incumbent, drew 51 million viewers. The Harris-Trump debate is expected to pull in north of 70 million.

In June all Trump had to do was stand back and let events unfold. As a result, he came across as calm, informed and statesmanlike. With Harris, it will be vastly different. It was always going to be a grudge match, and that was before he questioned the vice president’s racial identity, asking “Is she Indian? Or is she black?”

To this add that Harris is almost 20 years younger and a woman, and you have what some might consider a perfect storm heading Trump’s way. How will he cope?

The last woman candidate he took on in debates was Hillary Clinton in 2016. On one occasion he began following her around the stage, prompting accusations that he was “stalking” her. Given the backlash, he is unlikely to try the same with Harris.

So far Harris has two styles: upbeat, or tough and no-nonsense towards what she calls Trump’s “type”. Both play well among women voters.

Trump might have been able to cope with Harris taking the spotlight and her rallies pulling in huge crowds. Everybody gets a honeymoon. But now the numbers have come in. In a New York Times/Siena poll published on Saturday, Harris was ahead of Trump in the key states of Wisconsin, Pennsylvania, and Michigan by four points - 50% to 46%.

It is not a huge margin, but having spent the race neck and neck with Biden or slightly ahead, it is the wrong direction of travel for Trump, particularly with the opportunities Team Harris has coming up to build on that lead. With the “big mo” on her side there could be no stopping her.

But let’s get a grip. There is a long way to go before November and Harris is vulnerable on several fronts. For a start, she is yet to do a major television interview. Her record in office, her past in general, has not been subjected to the kind of scrutiny usually levelled at candidates for the presidency.

Her sentences have been known to wander and turn into “word salads”. Though Trump has done his fair share of wandering off-topic, on a good night he is sharp, punchy and to the point. And he is a past master at getting under an opponent’s skin.

Crucially, on the two subjects likely to dominate the election, the economy and immigration, the Biden-Harris record is weak. Another “w” word, not as voter-friendly as weird, and one likely to cause Harris serious trouble if Trump can make it stick.