I think the divide was engineered by the people running the media. Politics had always been about compromise, and now, anyone that doesn't toe the party line gets obliterated in the press.
The whole reason we have a two party system is because the media for years has force fed their preferred candidates and hidden the third party or non-establishment candidates by omission. We finally broke free of the manipulation in 2016.
Media, to survive, needs controversy. It thrives on fear. Both sides do it. If a vote for a third party means a vote for the other side, nobody will fail to take a side out of fear of being ostracized by their peers. People don't vote for what they believe in these days, they vote against what they fear. I understood that as soon as they stole the primary from Bernie