There are wealthy Democrats throwing money at the 2018 midterms, on track to be the most expensive election in U.S. history, but nobody in either party comes close to Republican mega-donor Sheldon Adelson and his wife, Miriam. With a recent $25 million donation to the GOP super PAC the Senate Leadership Fund, the Adelsons have now given Republicans $113 million through September to help them hold both houses of Congress, surpassing the $82.6 million the couple spent during the entire 2016 election cycle.

The late cash infusion by Adelson, a casino magnate worth an estimated $33.4 billion, is the "new benchmark for the most any individual household has spent on one election — including campaign committees, parties, and PACs — since the Citizens United Supreme Court decision in 2010," Roll Call reports, citing OpenSecrets data. "The rankings by OpenSecrets do not include donations through 501(c)(4) 'dark money' groups."

Thanks largely to this unprecedented political largesse, Republicans have passed Democrats in cash for the final stretch of the 2018 campaign, CNN reports. The Adelsons contributed two-thirds of the Senate Leadership Fund's haul last month, and a good share of the House GOP super PAC's windfall, too. The Adelson-flush GOP super PACs have at least evened out the advantage individual Democrats had from outraising their GOP rivals in competitive races.

"There's an intensity to these midterm elections that has been boiling since Election Day 2016," says Sheila Krumholz at the Center for Responsive Politics. But the small-donor furor fueling the Democrats "may not matter as much" on Election Day if one or two large Republican donors can make up the difference. That money may not overcome Democratic enthusiasm to vote in House races, but ProPublica has a long look at Adelson's healthy return on investment. Peter Weber