Maine’s senior U.S. senator, Republican Susan Collins, is facing political heat at home after a string of votes that defied President Donald J. Trump and the conservative base—threatening her viability ahead of the 2026 midterm elections.

According to Morning Consult’s latest quarterly survey, Collins’ disapproval rating among Maine voters has surged to 54%—the highest in the eight-year history of the firm’s tracking. Just 38% of Mainers approve of her job performance.

It’s a dramatic slide from her fourth-quarter 2024 numbers, when she held a modest 47% approval rating. Even then, signs of erosion were evident, as her numbers had already dropped from the previous quarter.

Collins, 72, who has long positioned herself as a “moderate” Republican, now finds herself out of step with a Republican Party that has rallied firmly behind President Trump’s America First agenda. Her recent votes only deepened that divide.

The most consequential break came in July, when Collins was one of just three Republicans to vote against Trump’s landmark “one big, beautiful” bill—legislation heralded by conservatives for slashing wasteful spending, reforming Medicaid, and unleashing economic growth. The bill was signed into law on July 4, just after the polling window closed.

Collins attempted to justify her opposition by pointing to rural healthcare concerns and proposing a tax hike on ultra-wealthy individuals—those earning over $25 million a year—hardly a popular move among fiscal conservatives.

“My vote against this bill stems primarily from the harmful impact it will have on Medicaid,” Collins wrote on July 1, adding that nearly one-third of Maine’s population depends on the program.

She acknowledged some support for conservative reforms, such as work requirements for able-bodied adults, but said the bill’s $5.9 billion reduction in Medicaid funding over the next decade could threaten rural hospitals in Maine.

That reasoning has done little to reassure the Republican base, many of whom view Collins’ vote as a betrayal—not just of President Trump, but of the priorities of working-class Americans tired of runaway spending and broken entitlement programs.

The White House is reportedly exploring alternatives to Collins should she reverse course and opt not to seek reelection, though for now, she says she intends to run in 2026. No primary challenger has emerged, but that could change as conservative frustration intensifies.

Despite the blowback, Collins remains chair of the powerful Senate Appropriations Committee and is sitting on a sizable war chest. According to FEC filings, she has raised $6 million this cycle and holds $5 million in cash on hand. A super PAC supporting her has added another $5.6 million in the first half of the year, and the NRSC is already running ads in her defense.

Collins’ team pointed to a separate Pan Atlantic Research poll from May that showed slightly better numbers—49% favorable to 45% unfavorable—but critics argue that Collins’ consistent breaks with Trump are beginning to catch up with her in a state that delivered key swing support to the President.

Maine GOP Executive Director Jason Savage issued a statement defending the senator, saying Collins “has been doing a tremendous job” and that “her work has impacted every community in the state.”

Whether Maine Republicans agree with that assessment in 2026 remains to be seen.