Over the six weeks since Kamala Harris succeeded President Biden as the Democratic presidential nominee, Donald Trump has charged relentlessly that she’s a radical whose views are out of step with voters.

“She’s a Marxist. She’s a fascist,” the former president declared last week, weirdly combining labels that normally contradict each other.

Trump claimed, without a shred of evidence, that Vice President Harris, whom he has dubbed “Comrade Kamala,” “wants this country to go communist.”

Trump has openly explained his strategy to reporters: “All we have to do is define our opponent as being a communist or a socialist.”

But his wild punches aren’t landing.

A barrage of public opinion polls shows that Harris has risen steadily in voters’ eyes and holds a narrow lead in the national popular vote. A Wall Street Journal poll released last week found that the vice president is viewed positively by 49% of voters, a gain of 14% since July.

The same poll found that 59% of voters consider Trump “too extreme” to be president, but only 46% consider Harris too extreme. (That number, 46%, roughly matches already committed Trump voters’ share of the electorate.)

So why is Trump’s free-swinging rhetoric failing?

For one thing, Harris isn’t — and never has been — a Marxist, and most voters appear to recognize that.

In her abortive presidential campaign in 2019, she cast herself as a progressive — but she was still closer to the center than candidates like independent Vermont Sen. Bernie Sanders, who (unlike Harris) describes himself as a democratic socialist.

To be doubly certain, I consulted a leading historian of American Marxism, Paul Buhle, a retired lecturer at Brown University. He said he had looked into Harris’ history and found no evidence of Marxist leanings. “It’s a slur,” he wrote in an email.

For another thing, Harris has moved quickly and effectively to define her positions as squarely within the mainstream of current Democratic thinking: liberal, but a long way from anything resembling Marxism, which calls for government ownership of major industries.

At the Democratic convention in Chicago, and in her interview with CNN last week, Harris made it clear that she has abandoned several of the progressive policies she briefly adopted in the heat of her campaign in 2019.

Her convention-speech promise that she would work with “small business owners and entrepreneurs and American companies to create jobs” was pro-capitalist enough to draw mild yelps from a few progressive critics.

She has made some arguably progressive campaign proposals, including a federal ban on “price-gouging” by grocery stores; Trump denounced the idea as “Soviet-style price controls.” But it turned out to be broadly popular: An Economist-YouGov poll last month found that 60% of voters like the idea, including about half of Republicans.

Campaign strategists from both parties say Trump’s attacks on Harris suffer from another flaw: They’re scattershot and unfocused. In addition to calling her both a communist and fascist, Trump has argued both that Harris is more liberal than Biden and that she would continue the president’s policies.

“He hasn’t settled on what his argument is,” said Doug Sosnik, a Democratic strategist who helped President Clinton win reelection in 1996. “I think he’s tried out about eight different arguments.”

Several Republican strategists say they think Trump is aiming at the wrong target — firing up enthusiasm among voters who already support him, but offering little to undecided voters.

“Name-calling is great for turning out your base, but it isn’t going to work for voters in the middle,” said a GOP strategist who asked not to be identified as he critiqued his party’s nominee. “People already know her record. They want to know how the candidates are going to make the economy grow. … Every time he’s calling her a name, he’s not talking about the economy.”

“Harris is succeeding in casting herself as a change agent,” said Alex Conant, a former advisor to Republican Florida Sen. Marco Rubio. “In 2016, one of the reasons Trump won was that he claimed the mantle as the change candidate. He said he would ‘drain the swamp,’ and that appealed to independent voters. But I can’t remember the last time I heard him use that phrase.”

The strategists say Harris still has vulnerabilities that Trump could exploit more consistently than he has.

They said a more effective campaign would tie her more closely to Biden’s economic record, since most voters hold the president responsible for high prices and think Trump could do a better job.

“Trump needs to make the election a referendum on the Biden-Harris record,” Conant said.

And they said some voters have doubts about Harris’ ability to lead in a crisis, a measure on which Trump outscores her in surveys.

Trump’s television commercials, designed by the professionals who run his campaign, already focus on those themes. Instead of white-hot charges like “Marxist,” they use a more traditional — and more accurate — label: “San Francisco liberal.”

But in public appearances, Trump has been unable to stick to that more disciplined message.

While Harris continues improving her image among undecided voters who may choose the next president, Trump’s rally speeches are exercises in self-indulgence.

The name-calling and wild punches aren’t helping him win more votes. But Trump wants to be Trump, free from the discipline his aides have sought vainly to impose. He just keeps swinging away.