NEW YORK, Nov 17 —Elizabeth Warren, one of the leading Democratic presidential candidates, has stepped up her assault on billionaires — a rallying cry popular with her base, but one that could stymie her efforts to garner wider support among US voters.

The 70-year-old US senator from Massachusetts on Thursday unveiled a new ad in an appearance on CNBC, a business news network that often criticises her, in which she takes on the ultra-rich.

The one-minute campaign ad shows clips of several leading businessmen criticizing her plans for a wealth tax and predicting economic ruin if she is elected to succeed Donald Trump, a billionaire himself.

"The vilification of billionaires makes no sense to me. It’s bull,” says investor and hedge fund manager Leon Cooperman, one of the men targeted in the ad. After he speaks, a note appears on screen — "charged with insider trading.”

"I’m most scared by Elizabeth Warren,” chimes in Silicon Valley investor Peter Thiel, who is identified on screen as a "Facebook board member and major Trump donor.”

Then the viewer sees Warren at a campaign rally, challenging America’s most wealthy to pay up to help reduce income inequality in America.

"Pitch in two cents so everybody else gets a chance to make it!” she says to cheers from the crowd.

The ad marks a new phase in the White House strategy of Warren, who has put her fight against the rich at the heart of her campaign.

"All of this is a publicity stunt,” said Capri Cafaro, an executive in residence at American University’s School of Public Affairs and a former Democratic member of the Ohio state senate.

"She’s showing that she has the toughest talk when it comes to taking on the billionaires and standing up for working families,” she told AFP.

‘Billionaire tears’

In her campaign, Warren often fluctuates between using irony and outright scorn for those she doesn’t like.

When Cooperman blasted Warren as "disgraceful,” the Wall Street foe’s campaign Twitter account fired back: "ok billionaire” — a twist on the "ok boomer” meme that has gone viral among those fed up with their elders.

When Bill Gates expressed concern that he would have to pay US$100 billion under her wealth tax, her team launched a tax calculator for billionaires on her website, and she offered to meet the Microsoft founder and philanthropist to explain her policy platform.

When one clicks on the tax calculator, you can enter your net worth and get a rough estimate. If you’re Gates, Cooperman or former New York mayor Michael Bloomberg, there are dedicated links that automatically inputs net worth. For Gates, it’s US$107 billion.

Bloomberg is meanwhile mulling his own presidential bid.

Warren is also selling anti-billionaire swag on her site. One mug has the mocking phrase "Billionaire tears.” Buttons promoting the wealth tax — which would be a two per cent levy on fortunes exceeding US$50 million — say "two cents” and show two pennies.

Cooperman is always ready to take a swing at Warren, but he’s not the only one.

Former Goldman Sachs chief Lloyd Blankfein — who also appears in the campaign ad — said he was surprised by being included, and noted: "Maybe tribalism is just in her DNA.”

JPMorgan Chase CEO Jamie Dimon lamented that Warren was "vilifying” the rich, telling CNBC: "I think we should applaud successful people.”

Mark Cuban, who owns the NBA’s Dallas Mavericks, accused the senator of "misleading the public” with proposals that he suggested would not work, criticizing in particular her Medicare for All health plan.

Amid all the swirling controversy and tit-for-tat attacks, will Warren’s strategy pay off?

After running neck-and-neck with former vice president Joe Biden in several opinion polls, earning more than 20 per cent support in some surveys, a Reuters-Ipsos poll published Friday showed her trailing off at 13 per cent, behind Biden and fellow Senator Bernie Sanders at 19 per cent each.

According to Cafaro, some voters already sceptical about Warren’s many policy plans could be turned off by her harsh words for the rich.

"But if you’re someone that does feel that billionaires need to pay their fair share, this is going to make you even more firmly committed to her candidacy,” the analyst added. — AFP