What is the risk that Trump negates the results of the election in November and stays in office? It isn’t likely that he could simply refuse to leave office if he lost. The other branches of national government – Congress and the Supreme Court would likely stand against him out of basic commitments to bourgeois democracy. And the military would probably back their position.
And although he has now threatened it, Trump cannot cancel the vote because elections in the US are governed by subnational states and administered locally. But this doesn’t mean a coup isn’t possible.
To begin with, the very thing that prevents Trump from dictating the election's terms nationally allows his party to intervene, rig, suppress, and legally challenge the vote in states and counties across the country. Indeed, they are hard at work on that already.
Add to that the pandemic and a defunded postal service that is now run by a Trump mega-donor who is busy ousting top USPS officials, which will make basic vote counting an enormous, time-consuming task that could take days or even weeks.
These conditions could very likely lead to widespread, aggressive Republican protests at local polling stations and other places where ballots are being counted. In 2000, highly coordinated Republican "riots" took place in Dade, Seminole, and other counties in Florida where local election officials were still trying to determine final tallies. Those demonstrations gave cover for the Supreme Court to make the highly unorthodox move to intervene and decide the election for George W. Bush before the recount had been completed.
Now imagine a heavily armed version of that by Three Percenters, Oathkeepers, Proud Boys, and legions of angry Trump supporters (in coordination with the national party) in election districts across the country.
Imagine also Trump sending Federal agents (US Marshals, DHS, Border Patrol) to Democratic states and election districts where he claims to have evidence of election fraud.
Together, these are the ingredients of a potentially successful coup - carried out with enough semi-legality that other institutions of national governance (including the military) may decide that they either can’t or won’t intervene.
The question then is how to respond. It will take millions of people in the streets day and night – confronting armed Trump supporters, Federal agents, or both – to prevent a stolen election if the situation begins to break that way.
In some sense we have already had dress rehearsals in the past few months – mass social movements, counter-insurgency directed by the president, and reactionary paramilitary forces on the streets calling for civil war.
Joe Biden hardly inspires the kind of militant social upheaval we have seen since the murders of George Floyd and Breonna Taylor. But if Trump is allowed to steal the election the US will have collapsed into full authoritarian rule the consequences of which would be long-lasting if not permanent. The possibilities of radical social and ecological change so desperately needed now will be not just off the table but gone for good, and the ghastly agenda of white nationalism will be in full flower.