You’re neither taking into account the winner-take-all states nor acknowledging the more important poll internals: Trump is overwhelmingly named as best for the economy, national defense, immigration, etc.
Named as the best != 50%.
In other words he at best gets 40%. He’s not a uniter he’s a divider. I used to like him and thought it would be great for him to shake things up. But damn...after the past month or two—I have evolved ;-)