AN EXCELLENT EDITORIAL FROM THE WALL STREET JOURNAL: The Poison of Identity Politics: The return of white nationalism is part of a deeper ailment.

The White House nonetheless issued a statement Sunday saying Mr. Trump “includes white supremacists, KKK, Neo-Nazi and all extremist groups” in his condemnation. As so often with Mr. Trump, his original statement missed an opportunity to speak like a unifying political leader.

Yet the focus on Mr. Trump is also a cop-out because it lets everyone duck the deeper and growing problem of identity politics on the right and left. The politics of white supremacy was a poison on the right for many decades, but the civil-rights movement rose to overcome it, and it finally did so in the mid-1960s with Martin Luther King Jr. ’s language of equal opportunity and color-blind justice.

That principle has since been abandoned, however, in favor of a new identity politics that again seeks to divide Americans by race, ethnicity, gender and even religion. “Diversity” is now the all-purpose justification for these divisions, and the irony is that America is more diverse and tolerant than ever.

The problem is that the identity obsessives want to boil down everything in American life to these categories. In practice this means allocating political power, contracts, jobs and now even salaries in the private economy based on the politics of skin color or gender rather than merit or performance. Down this road lies crude political tribalism, and James Damore’s recent Google dissent is best understood as a cri de coeur that we should aspire to something better. Yet he lost his job merely for raising the issue.

A politics fixated on indelible differences will inevitably lead to resentments that extremists can exploit in ugly ways on the right and left. The extremists were on the right in Charlottesville, but there have been examples on the left in Berkeley, Oakland and numerous college campuses. When Democratic politicians can’t even say “all lives matter” without being denounced as bigots, American politics has a problem.

We have the worst political class in our history, and a dysfunctional political culture.