FORT WORTH, Texas—Leaders of the Make America Healthy Again movement had aimed to cement their alliance with the Make America Great Again movement, promising to spend $100 million to boost Republican candidates in the midterm elections.

But at a recent MAHA event at the swanky Willard Hotel in Washington, that message didn’t seem to have gotten through to Mark Gorton, who gave more than $1 million to support Robert F. Kennedy Jr. presidential bid in 2024 and is listed on the MAHA PAC’s website as co-president.“It’s not an important election,” he said when asked why he hadn’t donated recently to the MAHA effort to support Republicans in the midterms.

“I don’t actually really like being involved in politics.”

The MAHA-MAGA marriage is tenuous—and one reason is the frailty of Kennedy’s political apparatus. Most of the donors who gave last cycle to boost Kennedy and later his alliance with Trump are missing in the midterms.

Allied MAHA super PACs and nonprofits have spent far less than the $100 million promised, dropping only about $4 million in support of candidates since January 2025, according to federal election filings and news releases.

Gorton said despite voting for Trump in 2024, he is a registered Democrat and would love Democrats to embrace the MAHA movement. This cycle he has donated to Democratic groups, including one that advocates for safer roads and endorsed Democratic Socialist Zohran Mamdani’s bid for mayor in New York.

Many who rallied to the MAHA cause have been disappointed on issues like Trump’s seeking to boost production of the herbicide glyphosate, used in Roundup, for national-security purposes, said Jeff Hutt, who worked on Kennedy’s presidential bid. That means few are excited to give to Republicans, he said.

“Zero promises were kept.”Other disappointing factors, according to activists: the Iran war, the Centers for Disease Control and Prevention’s continued recommendation of Covid vaccines, and Trump’s rollback of environmental protections. Top Kennedy ally and adviser Calley Means resigned from the Trump administration Thursday, frustrated by the amount of sway corporate interests had in food policy, the Journal previously reported.“President Trump is absolutely committed to the MAHA agenda,” Kennedy said last week. “We’ve done more over the past two years than probably all the HHS secretaries put together.”

Dimming MAHA support is piling onto Republicans’ woes in this year’s midterm elections, in which the House and Senate are both seen as up for grabs. If Democrats are able to take one or both chambers, they can halt Trump’s agenda, kick-start investigations into his administration and launch impeachment proceedings into him or members of his cabinet.

Trump won his 2024 bid by doing better with nearly every demographic group, but his support from the MAHA community might have been critical in some swing states, such as Michigan.

Allies describe the super PACs and their accompanying web of nonprofits as hapless and rudderless, with their leader Tony Lyons, who is also Kennedy’s book publisher, little engaged and hard to get hold of. With just weeks to go before the midterm elections, Lyons was in London, supporting comedian and MAHA activist Russell Brand, who is on trial for charges of rape and sexual assault. Lyons has said Brand is falsely accused.

Two people in the president’s orbit said they advise donors to stay away from the MAHA groups.

One of the groups, despite spending little on elections, since January 2025 spent roughly $1.5 million on operation costs including event food, hairstyling, and consultants, including social-media influencers. Lyons and other PAC representatives didn’t respond to requests for comment.

Meanwhile, a recent gathering of MAHA leaders and corporate executives drew both the ire of grassroots health activists and frustration from White House officials, who feared the summit appeared to be selling access to Kennedy. Cancer-test maker Grail and retailer Walmart were among those who ponied up for sponsorships—at one point the price of the highest tier went for $400,000 and included face time at a small gathering with Kennedy, according to people familiar with the matter.A spokeswoman for Walmart confirmed participation but said that it got no special access to Kennedy.

Grail didn’t respond to a request for comment.

Some Republicans are still hoping MAHA can push them over the edge in tight races. Ken Paxton, who is running in the highly competitive Texas Senate race, has used his perch as the state’s attorney general to sue or investigate major drug and food companies. He met with a group of MAHA activists earlier this year, with his staff scribbling down ideas for more lawsuits and investigations, including into Dr. Anthony Fauci.

The MAHA groups backed out of sponsoring an October rally for Paxton—the groups were too disorganized to make it happen, according to a person familiar with the matter. But the MAHA Action nonprofit announced in mid-October that it would donate $1.3 million to another PAC supporting Paxton’s campaign, and Kennedy showed up to the Fort Worth rally to heap praise on the Texas attorney general’s work. Molly Maddux, an 80-year-old retired educator who showed up to the rally in a red sequined “Make Texas Great Again” jacket, said Paxton’s support for Kennedy’s MAHA agenda makes her more “gung ho” about voting for him. “I hate the chemtrails. I hate the vaccines,” she said.

Leaders in Trump’s orbit and White House officials have had mixed enthusiasm for cementing their alliance with MAHA in the two years since Kennedy joined forces with Trump, sometimes questioning the movement’s loyalty and alignment with Republican priorities.

Alex Clark, who hosts a popular MAHA podcast, visited the White House and told Kennedy and top Trump aides that about 15% of her audience had said they were on track not to vote without significant MAHA action.“If you’re still ignoring us at this point, it’s at your own peril,” said Clark.A White House official pointed to the new dietary guidelines, an executive order boosting regenerative agriculture and a push for more transparency around food ingredients, among other actions, as evidence the administration is committed to making durable MAHA changes.“President Trump and Secretary Kennedy will continue to take decisive action to deliver more wins,” said White House Spokeswoman Allison Schuster.

Amid the fissure, Democrats have spotted an opportunity. Rep. Alexandria Ocasio-Cortez of New York, who is considering a White House bid in 2028, has been meeting with MAHA activists to hear their concerns. House Democrats made “reclaiming MAHA” one of the pillars of their legislative agenda for healthcare in a September memo.“I think they’ve been watching what has been happening under this administration, realizing that they’ve been completely duped,” said Abdul El-Sayed—the Democratic nominee in Michigan’s highly competitive Senate race—who has a MAHA platform of his own.

But even MAHA fans who want their agenda to find life beyond the Republican party aren’t sure they’ll feel at home among Democrats.“The only thing that is holding MAHA in the Republican camp is, perversely, the Democrats’ reflexive hostility toward it,” said Charles Eisenstein, a former speechwriter for the Kennedy campaign, noting Democrats’ dislike of vaccine skepticism. Write to Liz Essley Whyte at liz.whyte@wsj.com and Eliza Collins at eliza.collins@wsj.com