The ever-growing amount of billionaire cash in elections is poisoning U.S. democracy, according to a report published Wednesday by the advocacy group Americans for Tax Fairness—which found that the top 100 billionaire families spent an eye-popping $2.6 billion on federal contests in 2024.

That’s more than twice the roughly $1 billion spent by individual billionaire donors in 2020, according to the group, and constitutes 160 times the amount of billionaire political spending since the 2010 Supreme Court decision Citizens United v. Federal Election Commission. That decision paved the way for the proliferation of super political action committees (PACs), a type of committee that can accept unlimited donations to spend on political activity.

Picking apart that $2.6 billion, there’s a clear partisan skew: 70% of that billionaire money went to entities supporting Republican candidates, while 23% went to entities backing Democratic candidates. The other 7% went toward independent candidates—such as presidential contender Robert F. Kennedy Jr., who is now a Cabinet secretary—and committees that gave to candidates from both parties who champion specific issues, such as cryptocurrency.

That skew is particularly pronounced when it comes to the competitive Senate races that determined control of the chamber in 2024.

Looking at Senate contests in Arizona, Michigan, Montana, Nevada, Ohio, Pennsylvania, and Wisconsin, the authors of the report found that nearly 80% of the total billionaire cash in these races—which tallied $1.14 billion in outside spending—went to outside groups supporting Republican candidates, compared to 20% used to support Democratic hopefuls.

“The billions of dollars of donations these oligarchic clans give candidates, parties, and particularly outside spending groups drown out the voices and concerns of ordinary voters, endangering democracy and distorting public policy,” the report states.

What’s more, “this undue influence by the billionaire donor class over our government—always a concern and already present in mostly indirect ways—has found its full, frightening expression in the second Trump administration with the ascendancy of Elon Musk, the world’s richest man and the biggest billionaire donor in the 2024 elections,” the authors wrote.

Musk’s ability to convert his extreme wealth into political influence in the Trump administration contrasts with reports that Musk pays relatively little in taxes. In 2018, for example, Musk paid nothing in federal income taxes even as his wealth soared, largely due to Tesla stock appreciation.

But Musk is just the “most notorious example of billionaires literally buying power,” according to the group. ATF highlighted that billionaire Linda McMahon secured a position as President Donald Trump’s education secretary after she and her ex-husband gave tens of millions to support Republican candidates, as did billionaire businessman Howard Lutnick, now the commerce secretary.

The report, titled Billionaires Buying Elections: They’ve Come to Collect, is the latest in ATF’s “billionaires buying elections” series, and according to the group it is the most comprehensive because it covers both direct billionaire giving and “traces the indirect routes billionaire cash can take through campaign committees contributing to each other.”

In its methodology section, the report gives the example of WinSenate—a super PAC that works to elect Democrats to the Senate—which did not report billionaire contributions, but received all of its funding from the Senate Majority PAC. Because the Senate Majority PAC got 19.9% of its funding from billionaires, the report counted WinSenate’s share of billionaire spending at 19.9%.

According to the report, other big-name Republican megadonors in the 2024 cycle included shipping supply magnates Richard and Elizabeth Uihlein and Israeli-American billionaire Miriam Adelson.

According to the authors of the report, billionaires need to be taxed more.

“Tax policy—which has the most direct impact on billionaire wealth—is perhaps the most obviously affected by the money-for-power billionaire bargain,” according to the group, which cites the current Republican push to extend parts of Trump’s 2017 tax cuts that primarily benefit the wealthy as part of a general trend in tax policy over the past four decades to decrease taxes on the wealthiest people and most profitable businesses.

“The self-reinforcing combination of booming billionaire fortunes and weakening campaign finance laws continues to threaten our democratic form of government,” according to the report. “As the outcome of the last presidential campaign amply demonstrates, until billionaires pay their fair share of taxes and we put effective curbs on their political spending, this threat will only grow.”

The report calls for solutions like bolstering the estate tax and implementing a wealth tax, such as the Ultra-Millionaire Tax Act, a bill that was reintroduced by multiple Democratic senators in 2024. The newer version of the legislation would place a 2% annual tax on the net worth of households and trusts between $50 million and $1 billion, and impose an 1% annual surtax—so 3% tax overall—on the net worth of families and trusts that is above $1 billion.