The county of Louisa in eastern Iowa is so rural that there is not a single stoplight on its roads, and its largest town, Wapello, boasts an appropriately wry nickname: “Capital of the World”.

The moniker is not entirely off-base, for decisions made here have, in their own way, reverberated across the globe. Louisa is among a band of counties along the Mississippi River that backed Barack Obama both times he was on the presidential ballot, before, like Iowa as a whole, flipping to Donald Trump in 2016 and growing increasingly Republican each time he was on the ballot.

In the town of Columbus Junction, where jobs at a slaughterhouse attract immigrants from all over the world, Araceli Vazquez-Ramirez, a community advocate with the local council of the League of United Latin American Citizens, remembers hearing from neighbors who planned to vote for the Trump two years ago because they believed the promises of improved healthcare and other economic benefits he campaigned on.

What they got instead, she said, was fear. Federal agents are not known to have conducted any raids in the town, but the population has grown frightened by Trump’s efforts to end temporary deportation protections for certain nationalities, and by aggressive deportation campaigns in major cities that appear to indiscriminately target anyone who appears foreign.

“They have detained people just by the color of skin. It’s not necessarily people that they know they don’t have documents,” said Vazquez-Ramirez, a naturalized US citizen born in Mexico. “I mean, I can be picked up any time.”

Those in the community who supported Trump “kind of regret it”, she said, “because all the things that are happening now”.

Across the country, evidence is building that the coalition that elected Trump to a second nonconsecutive term as president in 2024 is coming apart. Polls show his approval rating falling, including on electorally perilous areas like the economy and inflation, while Democrats have won several major off-year and special elections since he took office. Even where they have lost, results have shown voting groups that the president won in 2024 are shifting left.

“After the 24 election, Republicans were gleeful that they had found a path forward in a country that was moving quickly to becoming a majority of non-white citizens. They’d won over growing numbers of Hispanics and Blacks. They had also stitched together the working class that used to vote for the Democrats,” said Larry Jacobs, director of the Center for the Study of Politics and Governance at the University of Minnesota.

“The Democrats were in panic: they were losing the minority voters and the working class. What was their future? Well, it turns out the Republicans under Donald Trump have self-destructed and what looked so promising just two years ago is now looking quite ominous. It’s hard to see how the Republican party is going to bounce back any time soon.”

Trump entered office claiming a historic mandate, one he used as justification to set about remaking the US government, settle longstanding rivalries with foreign adversaries and use tactics unheard of in modern times against immigrants. But the public does not appear to have remained onboard for long.

Last October, the Center for Public Opinion at the University of Massachusetts Lowell found that Trump’s approval rating stood at 42%, exactly where Joe Biden was in April 2024. The data suggests that “all of that honeymoon period and goodwill from that election victory had really been lost” just nine months into Trump’s term, said director of survey research John Cluverius.

In the months since, public disapproval of Trump has climbed to the highest level of his two terms, according to a Washington Post-ABC News-Ipsos poll released this month. The militarized approach his administration took to his mass deportation campaign promise, which sparked confrontations in which federal agents killed two US citizens, has been a driver of this souring, despite efforts by the White House to change its strategy.

But the most damaging decision of Trump’s presidency thus far may be his decision to join Israel in a military campaign against Iran and spark a global oil crisis that drove up up gas prices across the United States.

“Everybody’s suffering from gas prices. We work for ourselves: gas prices hurt us when we have to fill up two or three times a week instead of once a week,” John Johnson, 78, a contractor who voted for Trump, said as he sat at a bar in Crescent Springs, Kentucky, a city whose Republican congressman, Thomas Massie, has repeatedly broken with the president and faces a primary challenge.

Mulling the war in Iran, Johnson said: “Is it handled right? I don’t think so. It could have been handled differently – diplomatically more so. But we’re there, let’s finish it, let’s do it right.”

LeShante Wade, a project manager and Democrat from Lawrenceville, a politically mixed Georgia city, said: “I don’t like way we’re headed. The higher economic expenses day-to-day and the cost of living have gone up.

“Every day is a chaotic event, along with the rising costs,” she added.

What neither party knows yet is if the economic fluctuations will be enough to break the uniquely tight bond Trump formed with his followers in the Republican voting base.

“I think people like me are still strongly Republican, and, you know, rightwing,” said Larry Toups in Sugar Hill, Georgia, which, along with Lawrenceville, is among a band of suburbs north of Atlanta where Democrats hope to build their power in elections to come.

“Trump doesn’t have any ulterior motivation. He is what he says he is, and that’s what he does.”

On 3 November, Donald Trump’s Republican allies will defend their control of the Senate and House of Representatives in midterm elections that are shaping up to be an inflection point in his second term. Historical trends favor the Democrats, as the party out of power, to retake control of at least the House, which Republicans currently hold by a historically small margin.

The Senate is expected to be a tougher haul for the opposition. The party’s path to the majority require winning seats in at least three states that backed Trump in 2024, along with Maine, where Republican Susan Collins has fended off every Democratic challenger since first taking office nearly three decades ago.

How far Trump’s own problems will trickle down the ballot and tar other Republicans will be key to determining if Democrats succeed. But as high-stakes as the election is, the arenas in which it will be decided are relatively few. While election analysts’ forecasts vary, the two parties’ efforts to gerrymander incumbents out of their seats combined with increasing partisanship means that the number of true toss-up districts are estimated to be in the teens.

“I think it’s quite possible that the public will remain unhappy with Trump, but that the number of seats that can swing is limited just because there are so many seats now held by Republicans … that Trump won by 15 or 20 points last time,” said Charles Franklin, director of the Marquette Law School Poll. His survey’s most recent data has found generic Democrats have a four-point edge with registered voters, and are up by 10 percentage points with those likely to vote.

In Trump’s first midterm, in 2018, Democrats picked up 41 seats, but Franklin said in order for that to happen again, Democrats would need even more popular support than what polls show they currently have built up.

“It could happen, and the public is pretty negative right now about Trump and the GOP, but still that’s not one that’s easy to foresee at this point,” he said.