What The Indiana Primaries Tell Us About Trump's Grip On The GOP

Tuesday night’s primaries in Indiana were not subtle. Five of seven Republican state senators who had blocked a congressional redistricting map favored by President Donald Trump lost their primary races to Trump-backed challengers. The message, delivered cleanly through the ballot box, couldn’t have been clearer.

Twenty-one Republicans in the Indiana Senate voted against a new congressional map that would likely have added two GOP-leaning U.S. House districts. Eight of those dissenters were up for reelection this cycle, and seven drew primary challengers who carried Trump's explicit endorsement. By Tuesday night, the Associated Press had projected wins for at least five of those challengers. Only state Sen. Greg Goode managed to hold his seat among the targeted incumbents. The rest are heading for the exits.

Trump's play here was neither complicated nor ambiguous. He targeted members of his own party, not for ideological apostasy or opposition to his signature policies, but for refusing to help the GOP fight back against decades of Democrat gerrymanders. It was a demonstration of leverage and political capital, and it worked.

The incumbents who lost weren't rogue progressives or even moderate Republicans, either. They were conventional Republicans who had largely supported Trump on major national issues, and didn’t expect to become Trump targets. That calculation turned out to be wrong, and the lesson other incumbents will draw is obvious: the scope of what constitutes a disqualifying defection is wider than many assumed.

And there are likely to be other victims of Trump’s wrath.

In Kentucky's 4th Congressional District, Trump has endorsed Ed Gallrein against Rep. Thomas Massie, a Republican who has broken with the president on the Iran war, tariffs, and quit a few other things. In Louisiana, Trump is backing Rep. Julia Letlow against incumbent Sen. Bill Cassidy, a physician who has pushed back against the administration's "Make America Healthy Again" agenda. Both of those incumbents were watching Indiana returns Tuesday night and learning something about their own futures.

CNN’s Scott Jennings made it clear that the elections signaled who controls the Republican Party… It’s Trump all the way.

"He's the boss of the party. He calls the shots in the Republican Party, and if you go against that, he will pour his wrath out upon you, and it doesn't typically turn out well." Jennings said.”If you look at what happened in Indiana tonight, and you're Thomas Massie tonight, or you're anybody else in a primary right now where Trump's on the other side of you, you've got to be thinking, this is a bad night for me."

Trump cleaned up in Indiana State Senate primary tonight. @VanJones68 and I analyze & debate presidents getting involved in state level redistricting matters on @cnn pic.twitter.com/LutBmNpX4h

— Scott Jennings (@ScottJenningsKY) May 6, 2026

The underlying data on Trump's standing inside the party makes all of this easier to understand, if no less striking. Back in March, an NBC News poll found that Trump had a 100% approval rating among MAGA Republicans - a number that CNN analyst Harry Enten flagged as essentially without precedent. "You don't have to be a mathematical genius to know you can't go higher than one hundred percent," Enten said. He was careful to note the distinction: "Now, there are some Republicans who disapprove of Donald John Trump, but they are not members of the Make America Great Again movement. The bottom line is this: if you are a member of MAGA, you approve of Donald Trump."

That's the context in which Tuesday's results make complete sense. Trump's grip on the GOP isn't merely rhetorical or cultural — it is electoral and operational. Indiana showed that the president is willing to spend political capital on state-level races to advance his agenda, even if tangentially. For Republican incumbents nationwide who have crossed him or are contemplating doing so, that combination — willingness and effectiveness — should worry them.