There is mounting evidence that the election was rigged and that, had the votes been counted accurately, he would have lost in a landslide. Currently, the election interference is going through the discovery phase in the courts with the collection of evidence. It's a painfully slow process.
The Trump team knows the court process is painfully slow. And that Trump owns the Supreme Court.
He thinks he owns it. They've stood against him on certain points and in those moments he chooses to disregard court orders. It's why his team has been insinuating that the courts are the enemy on national television. He knows that they aren't 100% loyal to him.