The dinner will be held on Saturday night in Washington. The last time a president DID NOT attend was 1981, when Ronald Reagan didn't go. He was in the hospital, recovering from an assassination attempt--and he still called in.
Trump will not be there. He cannot handle people telling jokes about him, and he loathes the press like a spurned lover.
So he will hold a rally instead, letting his supporters stroke his very brittle ego and make him feel like everything is going great.
It's hard to imagine a whinier and more emotionally fragile President. And he calls everyone who doesn't agree with him a snowflake. That's what the psychologists refer to as projection..."Psychological projection is a theory in psychology in which humans defend themselves against their own unconscious impulses or qualities (both positive and negative) by denying their existence in themselves while attributing them to others." (Sigmund Freud)