Former Speaker Kevin McCarthy has warned Donald Trump and other Republicans not to make 'stupid and dumb' personal attacks on Kamala Harris.

Harris, the first vice president of color, is the presumptive Democratic nominee after President Joe Biden dropped out of the race against Trump on Sunday.

Racist rhetoric by Republicans about Harris began almost as soon as Biden abandoned his reelection bid, calling her a 'DEI hire' among other insults.

McCarthy warned his colleagues this was a grave mistake that would only help Harris by driving moderates and independents away from the party.

'Two attacks I've heard Republicans give that are totally stupid and dumb to do is the DEI attack, OK?' he told Meet the Press on NBC.

'This DEI, that seems like a petty... Look, I disagree with DEI, but she is the vice president of the United States. She is the former US senator. These congressmen that are saying it, they're wrong in their own instincts.'

McCarthy also rubbished calls by fellow Republicans for Biden to step down as president, which would automatically elevate Harris to the top job.

'That would be an advantage for Kamala. Air Force One is very powerful when it lands somewhere,' he said.

'And you know what? Something will happen between now and the election. A hurricane or something else. And she'll be able to present herself as a leader. Or maybe there's some foreign policy.

'That is a mistake for any leader to go out and say that on the Republican side.'

Congressman Tim Burchett, most prominently, repeatedly mocked Harris as a 'DEI hire' who was only made Biden's running mate to show inclusion.

'One hundred percent, she was a DEI hire,' he told CNN, claiming she was on the ticket because Biden said during the 2020 campaign that he 'was going to hire a black female for vice president'.

'What about white females? What about any other group?' Burchett added.

He doubled down on Twitter, claiming: 'The media propped up this president, lied to the American people for three years, and then dumped him for our DEI vice president.' 

McCarthy was joined by other Republicans warning against personal attacks on Harris to avoid the risk of alienating moderate voters.

This is despite Trump uttering near-constant personal insults against political opponents and others in almost every speech or interview.

'It's certainly not the rhetoric that I would focus on. I would focus on her merit to do the job,' Congressman Max Miller, a former Trump 2020 campaign aide, told Fox News.

'This woman just isn't ready to be commander-in-chief of the country. And in my opinion, that's what Republicans should focus on, as opposed to do what Democrats do, which is to call out someone based off of their skin color or gender. 

'This is all about merit. And so I think DEI is the wrong hole to go down.' 

Another House Republican added: 'Personal aspersions don't work in politically successful campaigns. So yeah, let's knock that stuff off.'

Congressman Ryan Zinke said he didn't think Trump would 'be on the personal attacks', despite his long history of making them.

Congresswoman Marjorie Taylor Greene, however, ignored calls to knock it off ands claimed 'everyone knows' Harris was chosen for her race.

'She wasn't chosen because she was truly highly ranked amongst Democratic voters throughout the country. She was chosen for a reason,' she told Fox News.

'And it seems to be that her, unfortunately, her gender and maybe her skin color was part of that.'

Fox News didn't appear to get the memo either, as its pundits spent much of Tuesday night hammering the 'DEI hire' line. 

New York Attorney General Letitia James already used the 'DEI' attacks by Republicans to accuse them of racism.

She said Republicans were 'running scared' at the prospect of facing Harris at the election, and 'have nothing else other than racism and sexism'.

'When you have nothing else, unfortunately, you just appeal to the racist among us, the white nationalists among us. That's all,' she said.

'The reality is, is that Kamala Harris, Vice President Harris, is qualified. And, oftentimes, she's underestimated, but she's an overachiever.

'And that's why I have wholeheartedly endorsed her. And it's unfortunate that individuals are just amplifying racism and sexism, and it's totally inappropriate. And I will not dignify it with a response.'