UK and US voters are highly cynical. They express it differently.

It’s not just football versus soccer. Britain and America share a language and deep historical ties, but their political systems are an ocean apart.

That could be good news for President Donald Trump.

As Republicans in the United States search for clues about the political mood ahead of November’s crucial midterm elections, a parliamentary by-election in Makerfield, England, is demanding attention. It’s not just that the special election could kick off a chain of events ending in Keir Starmer being ousted as prime minister — the contest itself serves as an early test of whether the anti-incumbent anger that upended Western democracies in 2024 remains a potent force.

But a new analysis of POLITICO Poll results suggests British and American voters respond to that political frustration in different ways. While cynicism about politics is widespread and persistent in both countries, British voters, with an array of political parties across the ideological spectrum, are willing to abandon their party in search of an alternative.

American voters, by contrast, remain largely constrained by the two-party system — limiting just how far they can go in channeling their frustrations.

In the U.K., just half of those who voted for Starmer’s center-left Labour Party in 2024 plan to vote the same way in the next election, according to the survey conducted by Public First from May 8 to May 11.

Meanwhile, strong majorities of Americans — including 75 percent of Trump 2024 voters and 86 percent of voters who backed former Vice President Kamala Harris — plan to stick with their party, underscoring just how little voter movement there tends to be in the U.S.

“We have a far, far more fluid system, I think, even than in the U.S., so people will switch parties,” said Mark Shanahan, an associate professor of political engagement at University of Surrey in Guildford, England.

That could be a saving grace for Trump and the GOP as they brace for a midterm landscape more difficult than initially expected, a change fueled in large part by voters’ persistent economic anxieties. It’s easier for the British voters who elected Starmer in 2024 to move to a different party in the country’s multiparty system, but disaffected Trump voters have no real choice.

Trump’s rise to the White House in 2016 was powered by a coalition that included independents, disengaged voters and Americans who felt alienated from the political establishment. They helped him again in 2024.

Republicans trying to stave off a difficult midterms have since warned that the biggest danger for the party in November is not that those voters suddenly defect, but that they become disillusioned enough to simply not vote. It’s a turnout election, strategists and candidates from both parties keep saying, that will likely come down to whether Trump voters show up for the party even when he’s not on the ballot.

What they’re less worried about is Democrats finding a way to move large numbers of persuadable, frustrated Republican voters back into the fold, or to pick up steadfast partisans. That’s true even as voters keep making clear that they’re looking for change.

The POLITICO Poll reveals just how deep the sense of cynicism and pessimism runs among voters in both countries. In the U.S., 71 percent of adults say politicians only look out for themselves, including 79 percent of those who backed Harris in 2024 and 71 percent who voted for Trump.

There are similar frustrations in the U.K., where majorities of voters blame the politicians — not the system — for the country’s current political problems. In a poll conducted earlier this month by London-based Public First, a 45 percent plurality of U.K. adults say that the country keeps changing prime ministers because none of them are any good.

But the analysis from Public First finds an important distinction in how voters in the two countries channel their frustration at the ballot box. British voters appear much more willing to cross party lines.

In the U.K., the Labour Party rode to power in part by tapping into the support from cynical voters. But two years later, the Labour Party is hemorrhaging supporters. Fewer than half — 49 percent — of those who voted with the Labour Party in 2024 plan to do so again, while 13 percent plan to vote for the Green Party to its left and 13 percent for leading hard-right party Reform U.K., while the rest are divided among other parties or unsure according to The POLITICO Poll.

“What we are seeing, particularly since Brexit over in the U.K., is a dissatisfaction in what was never formally a two-party system, but had been a de facto two-party system pretty much since 1916,” said Shanahan.

The Conservative Party — the Tories, the party of Winston Churchill and Margaret Thatcher that battled with Labour for a century — has fallen out of favor, losing support to Nigel Farage’s Reform U.K. party. That break is similar to the MAGA vs. traditional Republican split in the United States — but the two-party American system forces the GOP to stay together in an at-times tense coalition on the right, while British voters can simply switch from Conservative to Reform.

That also spells trouble on the left for Starmer, whose popularity has plummeted and who is eager to quash an internal revolt that could eventually lead to his ouster. The Makerfield by-election on Thursday will determine whether Andy Burnham, the mayor of Greater Manchester and Starmer’s chief internal rival, is elected as Labour’s representative in Parliament, giving him the chance to challenge Starmer for the party leadership and potentially replace him as prime minister.

"As the electoral politics of the U.K. fragments, it can only take a few thousand cynical voters in each of a few hundred constituencies to switch a majority to a devastating defeat,” said Seb Wride, head of polling at Public First, POLITICO’s polling partner. “This is how, in 2024, Labour got into government with fewer votes than it got in 2019, and why most election modelling would now say they've lost that majority as quickly as they gained it.”

The POLITICO Poll in June found 64 percent of U.K. adults say they don’t trust Starmer and, in a separate question, 62 percent say he is not someone who keeps his promises. Labour suffered massive losses in last month’s elections, prompting the calls from Starmer’s own MPs for him to be replaced.

But as Starmer stares down that threat — fueled by some of the very voters who elected him into office in the first place — the challenges before Trump and the GOP are much different.

In the U.S., even the most cynical and disaffected voters still tend to stick with their party identities. Even among non-MAGA Republicans — the conservatives least loyal to the president, who do not self-identify with his MAGA movement and ideology — highly cynical voters are just as likely to stick with the GOP in the midterms as less cynical voters are, according to Public First.

"In the U.K., voters who are dissatisfied with the main party tend to have a third or even fourth option. In the U.S., they have one alternative, or the option to not show up,” Wride said.

Poll after poll shows early signs of Trump’s 2024 coalition fracturing, on issues including the cost of living and the Iran war, but when faced with the prospect of choosing between one main party on the left and one on the right, voters tend to hold their noses and pick the same one they have before.