“We know that extremist demagogues emerge from time to time in all societies, even in healthy democracies. The United states has had its share of them, including Henry Ford, Huey Long, Joseph McCarthy, and George Wallace. An essential for democracies is not whether such figures emerge but whether political leaders and especially political parties, work to prevent them from gaining power in the first place-by keeping them off mainstream party tickets, refusing to endorse or align with them, and when necessary, making common cause with rivals in support of democratic candidates. Isolating popular extremists requires political courage. But when fear, opportunism or miscalculation leads established parties to bring extremists into the mainstream, democracy is imperiled.”
(Steven Levitsky & Daniel Ziblatt, How Democracies Die, 2018, p.7)