Imagine a replay of the 2020 US presidential election — this time with a co-ordinated plan to reverse the outcome. Almost every judge — including many appointed by Donald Trump — dismissed last year’s challenges with the contempt they deserved. Senior Republican election officials, such as Georgia’s Brad Raffensperger and Michigan’s Aaron Van Langevelde, withstood a lot of intimidation to invalidate the count. Trump even telephoned Raffensperger to pressure him to “find” enough Republican votes to alter the result. He refused. The US election system ultimately held.

Those states plus more than a dozen other Republican-controlled ones are now enacting laws that would make it far easier for sympathetic judges to uphold the kinds of suits they threw out last year. Unless this can be overridden at the federal level, last year’s election could turn out to be a dress rehearsal for a successful bid in 2024. It is no exaggeration to say that America’s future as a democracy is in question.

The problem goes deeper than new voter suppression laws in swing states. An entire party is now beholden to the notion that Joe Biden is an illegitimate president — a belief that has rightly been dubbed “the big lie”. More than 60 per cent of congressional Republicans voted on January 6 to decertify last year’s electoral college results. They failed because Democrats hold a majority in the House of Representatives and because a courageous minority of Republicans refused to go along.

Many are now being challenged in primaries as traitors to their party’s cause. In the races for election oversight roles, such as Raffensperger’s position as Georgia’s secretary of state, endorsing the big lie is becoming a litmus test of a candidate’s loyalty. It is entirely plausible that by 2024 Republicans will control the House and have purged most non-believers from their ranks.

Biden’s overriding priority must thus be to pass a federal law to bolster national voting rules. Such a bill was passed in the House. But it has run into the Senate opposition of Joe Manchin, the Democratic senator from West Virginia, and Kyrsten Sinema from Arizona.

Manchin, in particular, has made it clear he will not vote for the bill unless it attracts bipartisan support. His stance is a cop out. Either a law is worth passing on its own merits or it is not. He should not give Republicans a veto over his decision. Manchin’s oft-professed fidelity to tradition also misunderstands US history. America’s Emancipation Proclamation that ended slavery in 1863 was enacted on a mostly partisan basis. The idea that historic American change has been the fruit of cross-party co-operation is also belied by the civil war.

Manchin’s dilemma is that he represents a state that voted heavily for Trump, which means his re-election is in doubt. West Virginia gave Trump his second largest margin of victory after Wyoming, which is home to Liz Cheney, one of the few Republicans still opposing the “stolen election” narrative. Cheney’s stance may well sacrifice her political future. Manchin’s aims to prolong his. But at what cost?

There is scope for Democrats to show flexibility. Not everything in the bill has to be retained. Moreover, the law would not override state laws that give legislatures the power to refuse to certify their electoral college returns. Those battles will have to be fought in the states. But it would overturn harsh state restrictions on voting and put an end to gerrymandering. Manchin is surely aware that US democracy is at a crossroads. The choices he and others make will be recorded in history.