Americans benefit when the best versions of the right and left are vying against one another. Today, Donald Trump leads the worst iteration of the right I have seen in my lifetime, creating a deep fissure in the conservative movement that may never heal. And a deeply flawed iteration of leftism is ascendant at the same time, as I argued in “Why Can’t the Left Win,” quoting seven constructive critics of its pathologies.

Among the most thoughtful responses was a letter from a a South African human-rights lawyer who has spent much of his adult life in the United States. “Many of the issues pursued by the Left are properly described as matters of human rights,” he began. “They seek to end marginalization that is based on arbitrary difference, and instead promote dignity and opportunity based on simple human identity. Those rights are inviolable because they are argued to spring from simple existence.”

He finds much to commend in that approach:

The foundations of human rights struggles - and triumphs - lie in perilous battles. Slavery, Nazism, apartheid and more. Each ethos was entirely incompatible with the basic communal principle of “do no harm.” A struggle against them was necessarily existential. They either had to be eliminated entirely, or suffered completely. A contrary view could neither be accepted nor tolerated. Its proponents had to be ruthlessly destroyed. In the battles listed above, that was the correct approach.

However, he added, “today, in developed democracies, that is no longer the case. There is considerable futility in adopting an ardent, classic human rights struggle for much of what is being sought by the Left. The nature of the struggle has changed. The goal is improving the peace that we have, not winning the war we are waging. The goal is to be able to live in the same street, not claim that street as ours.”