Your friend may be onto something. I think Trump supporters will take his defeat in stride for two reasons:
1. His support is largely transactional, not devotion.
2. Trump supporters understand that he could lose. They’ve been hearing it for months.
The antifa crowd, though, are truly devoted to their hatred of Trump. And they’ve been told this election should be theirs to win, and only fraud can keep Trump in office. Hunker down.