'Let's go!' Top economist applauds as Harris signals support for billionaires tax

An economist at the forefront of the growing global push for a billionaire wealth tax is welcoming news that U.S. Democratic presidential nominee Kamala Harris is embracing calls for a minimum levy on the United States' richest individuals.

"Let's go!" Gabriel Zucman, an economics professor at the University of California, Berkeley, wrote Tuesday in response to Semaforreporting on the Harris team's endorsement of taxes on ultra-wealthy individuals and large corporations proposed in President Joe Biden's budget for Fiscal Year 2025.

Semafor highlighted a "little-noticed portion" of an analysis released late last week by the Committee for a Responsible Federal Budget, which wrote that Harris' campaign "specifically told us that they support all of the tax increases on the high earners and corporations that are in the Biden budget."

That budget blueprint includes a 25% minimum tax on billionaire wealth, much of which is unrealized capital gains that are not currently subject to taxation. A recent analysis by Americans for Tax Fairness estimated that U.S. billionaires and centi-millionaires collectively held at least $8.5 trillion in unrealized capital gains in 2022—a massive untapped source of federal revenue.

U.S. billionaires have seen their collective fortunes grow by more than $2 trillion since former President Donald Trump—the GOP's 2024 nominee—signed into law massive tax breaks for the rich and big corporations. Trump has campaigned on extending the deeply regressive and unpopular tax cuts and slashing rates for large companies even further.

Surging billionaire wealth at a time when roughly two-thirds of Americans are living paycheck-to-paycheck has amplified calls for a minimum tax on the richest Americans. Zucman noted in a May New York Times piece that in 2018, U.S. billionaires paid a lower effective tax rate than working-class Americans for the first time in the nation's history.

"The idea that billionaires should pay a minimum amount of income tax is not a radical idea," Zucman wrote in May. "What is radical is continuing to allow the wealthiest people in the world to pay a smaller percentage in income tax than nearly everybody else."

Polling has shown that a 25% tax on billionaire wealth is extremely popular with U.S. voters across the political spectrum. A survey in March of last year by Data for Progress found that 87% of Democrats, 68% of Independents and third-party voters, and 51% of Republicans back the idea.

A spokesperson for the Harris campaign confirmed to NBC News on Monday that in addition to backing the push for a minimum tax on billionaires, the vice president supports raising the corporate tax rate from 21% to 28% as a way to help finance parts of her broader economic agenda, which includes an expanded child tax credit and substantial assistance for first-time homebuyers.

The campaign spokesperson called the move—which would still leave the corporate tax rate lower than it was when Trump first took office in 2017—a "fiscally responsible way to put money back in the pockets of working people and ensure billionaires and big corporations pay their fair share."