I don't even think he was going to, but now he's scrambling to do anything that will fire his base up to be louder than all the people he's managed to piss off so far. But especially considering the wall - I don't even think there was ever any practical planning for it or anything. I think it's something that just came out of his mouth at a rally one day, and now he's stuck with it because he said it and "build that wall" became one of his campaign slogans.