The 2020 presidential election was three months ago, but one of the biggest backers of the false theory that it was rigged against former President Donald J. Trump has not given up his hope of overturning the results. On Friday, Mike Lindell, the embattled chief executive of MyPillow who helped finance Mr. Trump’s legal efforts to challenge election results, aired a falsehood-laden film about election fraud on One America News. The network promoted the two-hour film, titled “Absolute Proof,” on Twitter Thursday, urging viewers to join Mr. Lindell “for a never-before-seen report breaking down election fraud evidence & showing how...