the craziest (or maybe the most recent so it is just in my mind) example of this that has legitimately blown my mind is the flip flop on the iraq and afghanistan wars. along with the 2000 elections insanity, the polarization of society really started ramp up then. i was legitimately threatened numerous times on top of being just generally accused of unpatriotic, hate the troops bullshit back in 2002 - 2004 when objecting to the american asian adventurism that suddenly became the zeitgeist at the time. the bloodlust after 9/11 was enough to make any objectors to afghanistan a seriously irrelevant minority but there were enough of us in the lead up to iraq, that it became politically inflamed and was really the beginning of the fox crowd going insane. republicans were
since trump, these people would have you believe that it was the liberals that ran us into that war guns ablazin'. it is utterly fascinating. and yes, i am fully aware that many prominent democrats voted and advocated for both invasions but they were not driving the bus at the time and did not have control. wolfowitz, rumsfeld, cheney, and the rest of the gang drove that whole thing and the objectors were dismissed as traitors, unpatriotic, hate the troops, why don't you wear the yellow ribbon, etc...
now they act like they were a bunch of objecting isolationists the whole time...and as someone who was relentlessly attacked for dissent, that has been utterly fascinating.