How Massie’s Kentucky primary may test Trump’s hold on the Republican Party 

That principled conservatism is what appeals to Joshua Crider, who lives in Greenup, Kentucky, on the far eastern edge of Massie’s district.

“Massie seems to me to be the same person he was six years ago — someone who wants to lower our national debt instead of adding to it,” Crider said.

He voted for Trump in 2016, 2020 and 2024 but has soured on the president in his second term for failing to live up to the promises he made on the campaign trail. He said he’s voting for Massie over Gallrein to serve as a check on the president.

“I feel Thomas Massie is exactly that. I feel like Trump’s endorsement of Ed is an endorsement to gain another ‘yes’ man,” Crider explained.

For Belinda Taylor of Union, Kentucky, Trump’s endorsement is not enough to convince her to back Gallrein yet.

“I’m a conservative Christian. I vote for borders, budgets, biology, babies and the Bible,” she said.

The retired educator says she doesn’t know much about Trump’s pick and wants to study the issues of both candidates critically before making her choice.

Though she’s voted for Massie in the past, she is wary of career politicians and is concerned he doesn’t support Israel, which is a sticking point for her.

“I probably won’t know who I will vote for until I walk in the booth," she added.

Kentucky has shifted redder and redder in recent years, as the Republican Party has peeled off disaffected Democrats and centrists. Trump carried the state easily in his three elections, increasing his voting totals in each one.

But the president has also become increasingly unpopular over the last year, and the midterms are seen as the first major electoral test of his second term.

Experts say Massie has the advantages of incumbency, such as name recognition and fundraising. But it remains to be seen how much damage Trump's attacks may do to his campaign.

Kahne believes Trump’s lagging popularity could bode well for Massie.

“I think Trump is going to get hit hard in the midterms, and I think the Republicans who stood up to him are going to stand to benefit from that,” he said.

Voss, meanwhile, pointed to the close poll numbers in the primary as evidence of Trump's sway.

“Political science estimates suggest that a Donald Trump endorsement does help in a Republican primary, and it helps significantly, which is why we even have a race,” Voss explained.

An Emerson College poll conducted in late March found that 46 percent of Republican voters in Kentucky said Trump’s endorsement makes them more likely to support a candidate.

Another 41 percent, however, said it has no impact, and 13 percent said it makes them less likely to support a candidate.

Voss sees the upcoming primary as a fork in the road for those Republican voters, caught between their allegiance to Trump and the ideals they share with Massie.

"Those Republican voters in Northern Kentucky have to choose between their pro-Trump stance and their conservatism," Voss said.

"We know they hold both, but we don’t really know what they’ll do when the chips are down and they have to go one way or another."

The true test comes on May 19 when the votes are counted.