The thing is, there always has been and always will be a group of people that wanted themselves to succeed regardless of what tole it took on another group of people. Most people wanted the country as a whole to succeed, thought it would be nice if the American dream was accessible to everyone, but only really cared about themselves succeeding.
What has changed is that one political party has convinced millions of people that the only thing that matters is hurting another group. That those people over there want to destroy your way of life, take your money, and take away everything you enjoy, so all you need to care about is electing people that will hurt them. Your success doesn’t matter right now because all that matters is hurting them. Give us some of your money and we’ll make sure that they don’t take more of it. They’ve convinced the rubes to act against their own self interest in the name of hurting other people more.
It’s not that most Americans don’t have a shared set of values. It’s that one party and its media arm has convinced millions of people that most of the media, doctors, scientists, universities, big businesses, actors, artists, anyone living in a city, everyone who wasn’t born in the US, are all conspiring against you to take away your money and freedom so you need to trust us.