“Mail-in ballots are inherently corrupt,” declared Donald Trump in July, without producing any evidence.

Yet just weeks later, he himself voted by mail in a Republican primary election in Florida. The US President has often voted by mail.

In fact, nearly a third of Americans vote by mail because it’s so convenient – a way to avoid long lines at polling stations. The first mail ballots of the midterm elections, which will determine control of Congress in November, are due to go out this week.

Yet Trump has for years railed against mail-in voting, blaming his 2020 election defeat on fraudulent postal ballots.

And since his return to power, he has turned these unfounded allegations into a campaign to end mail-in voting, part of wide-ranging measures by his administration that are aimed at bringing control of US elections under the federal government. Trump’s intense battle to give the US Postal Service more oversight of mail-in voting is causing mass disruption. And critics say it’s all aimed at orchestrating a Republican victory in November’s midterm elections.

Trump’s most devoted Make America Great Again (Maga) supporters have taken their cue from the President, believing that fraudulent postal ballots somehow cost Trump a second term in 2020.

In his second term, the President has relentlessly pressed Republican lawmakers to pass his SAVE America Act, which would (among other measures like valid ID and proof of citizenship when voting) get rid of mail-in ballots altogether – with exceptions for the military and for those who are ill or disabled.

However, there were simply not enough votes in the Republican-held Senate to pass this, and so the frustrated President changed tack and is targeting mail-in voting via one of his favourite procedural routes, the executive order.

This executive order gives the US Postal Service – a nominally independent branch of the federal government – the ability to refuse to deliver ballots to states that do not submit lists of eligible voters. Federal officials say the voter data will be used to identify noncitizens on state voter rolls. That’s another key theme for the President – the idea that people who are not Americans are fraudulently voting in large numbers, for his political opponents.

In a social media post late in August, Trump claimed that a Census Bureau analysis of more than 128 million voter records “proves that over 24,000 Noncitizens voted illegally” in the 2020 Presidential election and the final number will “explode” once the agency finishes its work. Critics say the methodology being used by the report is either disputed or unknown. Furthermore, the team behind it included people linked to a Trump-aligned think-tank, the America First Policy Institute, according to a Census Bureau employee cited by NPR.

Either way, 24,000 noncitizens voting out of 128 million would be just under 0.02 per cent. A study by the Brookings Institution found an average of four cases of mail voting fraud out of every 10 million mail votes cast across four general elections from 2016 to 2022.

Democrats see the President as trying to disenfranchise their voters, who are more likely to vote by mail. More than one in three Democrats voted by mail in 2024, compared with about one in four Republicans, according to estimates by the States United Democracy Center. As Trump railed against mail-in voting on the campaign trail in 2024, Democrats embraced the practice. The elderly and those living in rural areas far from polling stations have long voted by mail and now the very concept is embroiled in a legal battle. Eighteen per cent of black voters, one third of Hispanic voters and half of all Asian American voters cast mail ballots in 2024, according to the advocacy group Common Cause.

Unsurprisingly, this rule giving the hitherto humble US Postal Service a role in mail-in voting is being challenged in courts across the land. More than 20 Democratic-led states have sued to block the rule and said they will not comply with it. The Constitution gives states control over elections, argue their lawyers, who say this is a blatantly unconstitutional move by an administration that is trying to federalise control of voting. The Supreme Court has allowed the plan to go ahead on procedural grounds, but hasn’t said whether it’s legal. A federal judge in Boston blocked implementation of the executive order – the administration is appealing – and so the legal battle continues.

Even if ultimately the US Postal Service is allowed to refuse to send out ballots to states that won’t submit voter rolls for examination, the midterm elections are less than 70 days away and there may not be enough time left to implement a complex new system. The Postal Service has introduced regulations that include new mandates for the design of ballot envelopes, and individual bar codes. The US Postal Service has told states, “the visibility and law-enforcement benefits of the rule … are such that there is no compelling reason for any delay”.

Thus, there is every possibility that midterm election results in close races will be challenged by the President and his allies, who will argue that any mail-in ballots cast are invalid because they do not comply with these new rules. Trump has learned the lessons of the 2020 election, when his myriad legal challenges to Joe Biden’s victory were overturned by the courts. Now his administration is trying to rewrite the rules. Could the US Postal Service refuse to deliver ballots because the envelopes don’t have the right bar codes? That would cause absolute chaos. Watch how the complex legal battle plays out because the stakes are high and the Trump administration is ready for a fight.