At this point Trump's ranting and raving about stolen elections and election fraud is just to plant the seed in his cult members heads that the Midterm elections were stolen.
I guess we can call this "Pre-election Fraud" foundation laying. The more he says this, the more his base will believe it. It doesn't have to be true. But, if they believe it, that's all that matters to Trump. Trump brought 65 cases of voter fraud to court. He didn't win a single case.
It's your basic brainwashing. Trump has zero proof that the 2020 election was stolen. But, the more he says it, the more his cult members want to believe him.