The Future of the American Left, by David Brooks.
Tribalism is in the air, on the left as well as on the right. It is based on a scarcity mentality, the idea that life is a zero-sum war between us and them. It emphasizes division and conflict, not solidarity and cohesion. It draws out the authoritarian tendencies in any movement.
The more America is opened up to immigration by the other seven billion people on Earth, the more the billionaires of America will prosper and the less the American people will enjoy high wages and low rents.
Bernie Sanders had the right instincts in 2015 when he derided Open Borders as a way for the Koch Brothers get even richer. But by 2016, he shut up about that because he realized that the political hopes of the Democrats are so tied to a strategy of importing millions of ringers from abroad to demographically crush the GOP.