Trump Is Running To Be Rush Limbaugh
This explains it. Trump is not running for president. He is running to build the audience around which to launch the Trump News Network. And he has it. The people who voted for him in the primary are big enough a number. TNN is a viable business proposition. Losing all 50 states would give him the purest, most loyal audience. 20 million people? That's a lot. It's a sufficient number.