"The voting public should not be taken in by this political charlatan," Cooperman told CNN Business.

His comments come after Warren took her clash with billionaires to their home turf by airing ads on CNBC, making the case for a wealth tax aimed at easing America's inequality problem.

Warren's commercial called out Cooperman, who was charged by the SEC with insider trading in 2016. Those charges were settled when Cooperman agreed to pay a fine of nearly $5 million.

Cooperman, the son of a plumber who has pledged to give away his entire fortune to charity, took issue with Warren bringing up the "SEC baloney." He noted that he did not admit nor deny fault and avoided getting barred from the industry.

"Any attorney will tell you I won the case because there was no case," Cooperman said. "But what does this have to do with her qualifications to be president? I'm not running for office - she is."

He added that Warren "impresses me as a superficial, nasty hater that doesn't seem interested in dealing with facts."

Cooperman 'can't escape the tax'

Warren isn't backing down. She signaled on Friday plans to ramp up her ad blitz pushing for a wealth tax.

"Some of the scared billionaires who oppose it are going on TV and tweeting their complaints," Warren tweeted. "It clearly struck a nerve. But we need this tax to help working families-so we're increasing our ad buy."

Warren's campaign responded to Cooperman's latest remarks by pointing out the high stakes for the billionaire.

"We're going to tax Leon Cooperman's fortune of $3.2 billion," Saloni Sharma, Warren's national deputy press secretary, told CNN Business in an email.

Cooperman "can't escape the tax" because it will apply as long as he's an American citizen, Sharma said. If Cooperman renounced his citizenship, he would have to pay a 40% exit tax on every dollar of his fortune above $50 million, she said.

"We're going to be giving the IRS the teeth and the tools to make sure the billionaires pay up," Sharma said.

Warren has called for imposing a wealth tax of 6 cents on every dollar of net worth above $1 billion. Her campaign says the wealth tax could be used to pay for proposed programs such as universal child care, universal pre-school, canceling student loan debt and Medicare-for-All.

Warren's agenda is aimed at tackling America's inequality problem head-on. The top 1% of US households now controls $34.7 trillion of the nation's wealth, according to the Federal Reserve. The bottom 50% of families holds only $2.1 trillion.

"All we're saying is when you make it big, pitch in two cents so everyone else gets a chance," Warren said during her ad that aired on Thursday on CNBC, a network that often hosts the billionaires whose wealth the Democrat wants to tax.

Beyond the wealth tax, Warren has also called for breaking up Facebook (FB) and banning the fracking of oil and gas.

Blankfein warns against vilifying

Warren's aggressive agenda and her tough tone have sparked a backlash from other wealthy individuals.

Lloyd Blankfein, a registered Democrat and the former CEO of Goldman Sachs, has acknowledged the inequality problem and supports taxing the rich more.

However, Blankfein recently told CNN's Poppy Harlow that he fears Warren wants "cataclysmic change" to the US economy. Warren featured those comments in her CNBC ad and then called Blankfein out for getting a $70 million pay package in 2007, the year the Great Recession began.

Blankfein, who backed Hillary Clinton in 2016, responded by hinting at Warren's past disputed claims to Native American heritage.

"Vilification of people as a member of a group may be good for her campaign, not the country," Blankfein tweeted on Thursday. "Maybe tribalism is just in her DNA."

Warren fired another verbal shot at Blankfein on Friday.

"He ran Goldman Sachs while it misled its own clients in order to turn a profit, which helped create the 2008 crash," Warren tweeted. "His bank then took billions in backdoor taxpayer bailouts, and no one was held accountable."

Cooperman said he sent a letter to Warren late last month that, he complains, she never responded to. The letter, which Cooperman provided to CNN Business, suggested alternatives to a wealth tax, such as eliminating loopholes in the tax code and implementing a surtax on millionaires.

"The fact is, Senator Warren, that despite our philosophical differences, we should be working together to find common ground in this vital conversation -- not firing off snarky tweets that stir your base at the expense of accuracy," Cooperman wrote.
Yet the rhetoric has only gotten more heated in the weeks since he sent that letter.

Cooperman, however, said his letter was "respectful and, if I must say, was extremely well done."