Meet Dick and Liz Uihlein. They spell it like this, but they spell their company name like this. “Uline” — it sounds familiar, right? You’ve probably used their boxes. The Wisconsin-based company has grown to be much more than boxes. It’s a packaging supply giant with over 6,000 employees. The family comes across as unassuming in these corporate videos. But when it comes to politics, they’re anything but. The Mercers, the Koch brothers and Sheldon Adelson already have the name recognition, but the Uihleins may be the biggest Republican donors you’ve never heard of. They’re pouring their massive wealth into super PACs backing insurgent right-wing candidates, already spending roughly $26 million on federal elections this cycle. Candidates backed by Uihlein generally support the Trump agenda, sometimes veering even further to the right. “A proven conservative fighting for Mississippi values.” Earlier this year Mr. Uihlein gave $2.5 million to Jeanne Ives for governor in their home state of Illinois. She ran this ad against incumbent Bruce Rauner in the primary. “Thank you for signing legislation that lets me use the girls bathroom.” The ad was criticized as transphobic. “That’s exactly what, typically, a transgender man looks like —” “No, it’s not.” Ives lost. “Roy Moore, leadership we can trust.” Mr. Uihlein also gave over half a million dollars to super PACs supporting Roy Moore in Alabama. Moore’s campaign was compromised when several women accused him of sexually assaulting them as teens. “I trusted Mr. Moore, because he was the district attorney.” A Democrat ended up winning that Senate race. Mr. Uihlein contributed half a million dollars to a super PAC behind Patrick Morrisey. He turned the “drain the swamp” rallying cry into something resembling a terrorist threat in this campaign ad. “Let’s not just change Washington, let’s blow it up and reinvent it. That‘s better.” Morrisey won the Republican primary in West Virginia, after President Trump disparaged his controversial opponent. “Mr. President, if you are watching right now, let me tell you: Your tweet was huge.” Sometimes the Uihleins support outsider candidates who wouldn’t stand a chance without the money. Wisconsin voters hadn’t heard of Kevin Nicholson, a political newcomer trying to unseat Democrat Tammy Baldwin, the first openly gay senator. Then Mr. Uihlein donated over $7 million to super PACs supporting Nicholson. The Republican Party has endorsed a different candidate in that race. But polls suggest that Nicholson is now a strong contender. The Uihleins spend the most in their home states of Illinois and Wisconsin, but they fund candidates across the country. These megadonations are helping to shape the 2018 elections, while pushing the Republican Party further to the right.