Perhaps you don't understand the purpose of the future market numbers. Vegas isn't trying to predict a winner with the spread, moneylines, and future bets.
Oddsmakers and bookmakers have a different job than that.
You say Vegas was wrong, but at the time, they may have been the getting action they needed where they wanted it.
Because the line has moved so much, one could say they made an error and were wrong, but that fails to appreciate the dynamics of this marketplace. It's like saying a live ine is wrong, well after it's been posted and removed.
This is a moving target over many months. There is little reason to believe bookmakers are behind in their movements. Trump hasn't locked it up yet, but the people may think he has. This could be a problem if he doesn't get it.