Donald Trump and allies are seeding one of their most dangerous efforts to undermine US elections to date, seeking to elevate candidates who refuse to accept Joe Biden’s victory in 2020 to crucial offices where they could do significant damage in overturning the 2024 elections.

The former president has endorsed several Republican candidates running to be the secretary of state, the chief election official, in their respective states. If elected, these candidates would wield enormous power over elections, and could both implement policies that would make it harder for Americans to cast a ballot and block the official certification of election results afterwards. Ten of the 15 candidates running for secretary of state in the battleground states of Arizona, Georgia, Wisconsin, Michigan and Nevada have either said the 2020 results were stolen or that they need to be further investigated, Reuters reported earlier this month.

The endorsements from the former president underscore the enormous power that secretaries of state have over election rules and procedures, both before and after the election. One of the main reasons Trump’s efforts to overturn the 2020 election failed in many places were election officials, including Republican and Democratic secretaries of state, who refused to go along with his effort. If those officials are voted out of office next year, it would be a serious blow to the guardrails of US democracy.

“It is really troubling that Trump’s grip on the base of the Republican party may lead to the election of people who say that they believe the 2020 election was stolen from Trump,” Richard Hasen, an election law expert at the University of California, Irvine, wrote in an email. “That’s demonstrably false, but it does undermine the integrity of any elections that these people would be involved in running should they be elected.”

The candidates are seeking votes from a Republican electorate that continues to embrace the false belief that the 2020 election was stolen. Seventy-eight per cent of Republicans believe Biden did not win the election, according to a recent CNN poll. More than half of Republicans believe there is solid evidence Biden did not win, the poll found, even though no evidence exists.

Earlier this year, Trump endorsed Jody Hice, a Republican congressman in Georgia running to oust Brad Raffensperger, the current GOP secretary of state who rebuffed Trump’s efforts to get the election overturned. Hice, who appeared at a rally with Trump last weekend, objected to the counting of Georgia’s electoral votes and said he was not convinced Biden won Georgia, even though several recounts affirmed Biden’s victory there. Hice posted a photo on the morning of 6 January describing the day as “our 1776 moment”.

Trump has also endorsed Mark Finchem, an Arizona state representative he described as a “true warrior”. Finchem was at the Capitol on 6 January, and though he has said he did not enter the building, records show he was in contact with organizers of the “Stop the Steal” rally. “When you steal something, that’s not really a win; that’s a fraud,” Finchem said at a 5 January pre-rally. Finchem was also one of the most-vocal supporters of a shoddy, Republican-backed review of the 2020 election in Arizona’s largest county, celebrated by Trump, that failed to turn up substantial evidence of fraud.

In Michigan, Trump has endorsed Kristina Kamaro, who as a poll watcher in Detroit in 2020 and made unsubstantiated claims of fraud. More than 250 local audits and a Republican-led legislative inquiry have affirmed Biden’s win in Michigan.

“Donald Trump has made it his mission to sow doubt in our democracy. His endorsement of Secretaries of State who believe and spread the Big Lie is the next step in the effort to tip the scales in future elections,” said Jena Griswold, Colorado’s top election official and the chair of the Democratic Association of Secretaries of State. “More than ever we need election administrators who will respect the will of voters no matter the outcome of an election – our democracy is on the ballot in 2022.”