They don't care about facts. At this point I think it is fair to say they don't understand what a fact is. They prefer "alternative facts", which is another way of saying they will claim, without evidence, or even with overwhelming evidence to the contrary, that anything which aligns with their feelings or beliefs, or serves their purposes, is a fact, reality be damned.

"You know, the very powerful and the very stupid have one thing in common: they don't alter their views to fit the facts, they alter the facts to fit the views." - Dr. Who

Trump, today: "The MMR I think should be taken separately. This is based on what I feel."

Medical advice broadcast to the nation based on Trump’s feelings.