To Sen. Jon Tester (D-MT), there’s an urgent need to stop “billionaires from buying our elections.”

Tester often slams the wealthy and well-connected for trying to wield power in Washington, D.C., a phenomenon he attributes to the Supreme Court’s landmark 2010 Citizens United decision, which ruled it unconstitutional to restrict outside groups from spending cash on campaign advertising. But the Democratic senator has long relied on billionaires to cut him checks; they’ve wired his own campaign hundreds of thousands of dollars since 2006, and many are lining up behind Tester as he hopes to retain his Montana Senate seat in a 2024 race widely viewed as a toss-up, Federal Election Commission records show.