President Donald Trump is ratcheting up his attacks on Kamala Harris, the Democratic nominee for vice-president. He said on Friday she was “not competent” to be president.

Trump has been attacking Harris, the first Indian American and Black woman ever to run for president, from the day she was picked by Joe Biden, the Democratic nominee for president, as his running mate. The president had been far more indulgent before, saying, in July; she would be a “fine choice”.

Attacking Biden at a rally in New Hampshire on Friday, Trump cross-haired Harris. “Joe Biden is running on the most extreme far-left platform of any nominee in American history. And if our foreign adversaries were devising a plan to destroy the United States from within, all they have to look is at Biden-Harris– how bout her? Is she a beauty? What a beauty that is,” he said.

Trump picked on Harris’s own failed run for the Democratic presidential nomination. “She was terrible. And this would be your president? Possibly? I don’t think so. You know, I want to see the first woman president also, but I don’t want to see a woman president get into that position the way she’d do it. And she’s not competent. She’s not competent,” he said.

Harris, a former prosecutor and US senator, has not shied away from giving it back, without the kind of personal attacks and insults used by the president some times.

“At its most basic level, Donald Trump doesn’t understand the presidency,” Harris said in her prebuttal to Trump’s acceptance speech at the Republican convention. She was referring to the Trump administration’s handling of the Covid-19 epidemic that has killed nearly 180,000 American and infected around 6 million.

The Biden-Harris campaign has cited the president’s handling of the worst public health crisis in 100 years as its argument against him, seeking to tap into widespread disaffection among Americans with his response to the epidemic — 68% of those polled disapprove of his performance in an AP-NORC poll released Monday, the first day of the Republican convention.