There are a lot of factors that drive polarization. I think you’re getting at that we need to try to communicate with people in a way that promotes mutual understanding and a mutual respect of our shared humanity, rather than painting everyone in the cartoonish stereotypes current politics evokes all over the place. I do think that the type of dismissive NYT liberal op-ed pundit assholery that calls most of America “flyover states” contributes to making things worse. Thats’s something we should all aim for (radical, liberal, moderate, conservative, reactionary alike). I see some liberals trying for that, and some conservatives, but the forces we’re dealing with are:
a strong evangelical movement of politicized Christianity that sells conservative talking points as a kind of faithfulness
a massively polarized right-wing media like Fox/Breitbart/Limbaugh/etc. that throw out outrageous lies to polarize the base on an hourly basis
a useless corporate media that decides the narrative then goes investigating to find the facts that fit it (CNN, NYT, WSJ, etc)
a polarizing and generally useless left wing media that I’ve mostly just stopped reading out of sheer aggravation (MoJo, HuffPo, Alternet, etc)
campaign finance changes that allow billionaires to pay for candidates that fit their ideals, and spread propaganda during elections with no restrictions
social media and web forums that create echo chambers reinforcing false views, polarized views, and an us vs. them mentality that dehumanizes people that don’t agree with some set of tribal politics.
As individuals, we participate in that last part, and I agree we can do better (myself included), but we’re honestly a drop in the bucket of a machine that would be as full of polarizing garbage and misinformation even if there was no internet. In the early 90s Fox, AM radio, and the rest were already driving things, the NYT et al were as useless as now, and the Moral Majority and it’s cousins were already running full steam.
I’m all for being better to each other, keeping the importance of being civil and respectful of those who disagree in mind, and trying not to dehumanize fellow human beings even when they hold dangerous and foolish ideas. Still, it’s a drop in the bucket of a set of conditions that keep the polarization going, and even if every liberal was really nice, decent, and thoughtful in their interactions with conservatives (and I do think we should try to live up to being better human beings), I don’t think we’d see any groundswell of improvement.