'...Only 48 percent of Republicans think Trump should concede if Clinton is declared the winner...Many of Trump’s supporters think the election is rigged. Nearly half do not believe their votes will be counted, according to a Politico/Morning Consult poll... The most commonly cited danger of Trump refusing to accept the election outcome is that it could lead to violence.The idea isn’t so far-fetched. Trump rally attendees have physically and verbally abused protesters. Milwaukee County Sheriff David Clarke encouraged his fellow Trump supporters to take up pitchforks and torches following claims of a rigged election . And attacks on Clinton are even more vicious.'