I keep seeing this brought up on HN. Isn't it telling that you have to go back 70 years to find a good example? At that time, the Democratic Party was still in bed with the KKK. It's not relevant to today's politics.
Mothers Against Dungeons & Dragons certainly tried to cancel role-playing games in the 1980s and they were just the largest group to try and do so. The Dixie Chicks were cancelled in the 2000s for a single instance of political speech.
One could easily pull up stories of people in the 70s, 80s, or even 90s who were fired or ostracized for supporting homosexuality and gay rights. Left-wing causes like supporting unions or even more radical leftist politics was a firing offense deep into the 80s. The only thing that has changed over a couple of generations is that now those who were once on the receiving end of cancel culture have the power to turn the tables and people who grew up with the implicit assumption that their beliefs and behaviors were beyond reproach are learning what it means to face consequences for their speech or actions.
"Being fired for something" isn't the same as being cancelled. "Cancellation" implies a concerted campaign to pressure employers into firing employees. Being fired on the grounds that you've offended your employer or said something that is broadly unpopular are both awful, but they're different than "you've said something that offended a tiny minority of the population but they're threatening to call up our clients and slander us (and otherwise make business difficult) unless we fire you".
They did not fire you just because they disagreed, they did so because others would harass and complain until you were fired. Sorry if the attempt at making some sort of 'both sides' point went off the rails, but cancel culture was created by the right and was their exclusive domain for almost 60 years in post-war America. There was a large list of things that you were not allowed to say, to do, or even to be just because right-wing pressure groups and 'concerned citizens' would ensure that you had no job and no voice if they found out.
The only thing that is different now is that the shoe is on the other foot. I guess when some people find they no longer have license to be an asshole the transition can feel a bit uncomfortable and needing to learn about these things called 'consequences' that everyone else has been forced to endure must seem a bit strange.
I replied to "the culture where this kind of behavior is normalized and valued is relatively novel", with the Dixie Chicks as the "canonical example".
Surely, providing an older example that predates the Dixie Chicks, can be used to argue that the phenomenon is, indeed, older, no?