Donald Trump both disbelieves and believes in falsehoods, so that when he did thrive on his longstanding - the claim that Obama was not born in the United States - he's crazy like a fox in manipulating it because it gave him his political entrée onto the national stage. In order to make your falsehoods powerful, you have to believe in them in some extent. And that's why we simplify things if we say that Trump either believes nothing in his falsehoods and is just manipulating us like a fox or he completely believes them.