My view is that Trump has never actually lost anything, ever, in his entire life, and he simply cannot comprehend that he has been seen as the less popular option, so in his mind, it has to be corruption, that's the only reason he has lost now.
He will be shouting about fraud until the judges refuse to hear his case without sufficient evidence, at which point of course, they will be 'corrupt' as well.
Since Trump actually has no personal dignity to lose, he will make an even bigger spectacle of himself until people get bored, and then he will fade away.