Prof. Christopher Parker's work on right-wing movements is cited in an article for the The Guardian on how many people might believe the 2020 presidential election was stolen.
"Three months after an insurrection at the US Capitol, an estimated 50 million Republicans still believe the false claim that the 2020 election was stolen from Donald Trump, according to a recent national survey. But it’s far from clear how many Americans might still be willing to take violent action in support of that belief.
Christopher Parker, a political scientist who studies race and the evolution of US rightwing movements, said that a preliminary finding that 4% of American adults believed the election was stolen from Trump... it was also very possible that the attitudes of Trump supporters were shifting over time, Parker cautioned, and that the 4% figure from mid-March may already be shrinking."