I think we were just as polarized, if not more so, but we didn't have 24/7 ragebait egging us on to fight some more to drive up the engagement numbers. It's like someone watched the Star Trek ToS episode "Day of The Dove" and thought it was a great idea for a startup. But also, that was 1968, plus sa change and all that...
Most political scientists don't agree with this. The Wikipedia page provides a good overview: https://en.wikipedia.org/wiki/Political_polarization_in_the_...
By their metrics, clearly, they are correct. But reading some books lately that were either from or set during the mid-70s to early 80s, the same tired political tropes were already in the zeitgeist.
But also, from that link...
"Americans' views on gun control seem to stem almost entirely from their cultural worldview and how they position themselves in that cultural schema. Statistics do not persuade them to change their minds."
If true, stick a fork in us, we're cooked.