Trump does a lot of smart things in handling the press but trying to pick off communist Bernie supporters instead of defending and explaining capitalism, contrasting and showing why communism and socialism never works would put the nail in the coffin of conservatives giving him a chance.
Trump has a golden opportunity to shine and show why America was great before socialist democrats started destroying it and why the base should support him . The problem is who Trump really is, is not republican and the more he moves left the less likely I am to vote for President. If he goes out and brown-noses communist I am out.
His press statement reminded people Clinton stole the election or cheated against Sanders. Reminded people why they hate Clinton and allowed publicly be against the debate.
So Trump steps away from the debate after damaging Clinton and no loss to him.
If Trump was a general he would be Alexander the Great - because he is unconventional and brilliant out of the box when it comes to media politics.