To be fair on them (not that there’s much reason to give them that courtesy), most of the Trump supporters I encounter at my work and such seem to truly believe that a sizable majority of people in the country agrees with them and that everyone else is either some kind of hostile elite or a crazy fringe. If they really do believe something like that, then this is kinda self-consistent of them, since they would therefore believe that they cant lose a fair election, and therefore that them losing is evidence of cheating even if they don’t have clear evidence of how, but them winning would be evidence that, if there is any, it at least isn’t enough to change the outcome.