Again, you're making a huge assumption that is not tenable, given historical voting patterns, about 18-40 year-old voters not voting in large numbers. That's partly why Vegas odds and scientific polls have Clinton in the lead. I'm not a gambler, but if I were to place bets on any candidate, the "smart money" would be on Clinton, not Trump. Also, his general-election appeal among the electorate is much more limited and narrow than Clinton, so that means he has much smaller margin of error in terms of who votes for him, turn-out, etc. The question for Trump supporters is, how much money are they willing to bet on his winning in November based on those odds and based on the fact that his unfavorable/favorable ratios are the worst for a Republican nominee in modern election-polling history?