Four years before Sen. Josh Hawley, R-Mo., pumped his fist to a supportive mob that would soon overrun the Capitol Police and hunt lawmakers through the halls of Congress, the former Missouri attorney general needed a deep-pocketed patron. Naturally, he called on the man who helped bankroll former President Donald Trump’s rise: hedge-fund billionaire Robert Mercer, whom he would soon describe as a friend while name-dropping him to court support from far-right figures like Steve Bannon, a longtime Mercer ally. It’s unclear what came of Hawley’s meeting with Mercer, but the Club for Growth, which has received millions from the Mercer family, and the Senate Conservatives Fund, which also got Mercer donations, quickly became Hawley’s biggest financial backers, by far. Mercer’s daughter Rebekah kicked in a near-maximum donation to his 2018 Senate campaign for good measure.

While Charles Koch and his late brother David have dominated Republican fundraising in recent decades, the Mercers’ recent strategic investments in far-right candidates bought them a disproportionate level of influence in the Republican Party before culminating in an effort to subvert the election […]