I believe that stupidity is and has always been widespread and in normal times the more intelligent ideas have the widest subscription, even among the stupid. But when leaders fail to [be open, be objective, act in good faith, stick to the truth], then even the stupid can detect that they are being played and they rebel and seek alternative facts. So my theory is that leaders are currently gaming the populous rather than leading them, and that this is so obvious to everybody that trust in leadership and institutions has gone out the window.
Scott Adams has recently asserted that about 90% of what we are being told is not true. I'm don't concur with Scott on that figure, but clearly even smart people have lost trust in leaders/institutions. When the news refuses to report on 25% of newsworthy stories because they either make Trump look good or Biden look bad... when the news claims it's perfectly safe to protest BLM issues in the streets during a coronavirus pandemic... when even judges are clearly acting in bad faith (Julian Assange extradition case, Michael Flynn case)... when the Supreme Court becomes (or is perceived as becoming) the arm of a political party rather than an objective trustable institution, then the populous loses faith in the leaders/rules/institutions and we get widespread rioting, violence, a hell of a lot of stupid ideas, and perhaps hopefully some positive changed buried within all that somewhere.