In conservative and largely online circles, the term “NETTR” has gained traction. It stands for “no enemies to the right.” The underlying thinking is that those to one’s left are the enemies, and those to one’s right, just by mere placement, can’t be. It sounds good in theory: that “owning the Libs” matters most of all. In practice? It’s destructive in both the short and long term. The civil war raging on the Right is not likely to die down anytime soon. For those who value established principles and basic decency, the desire to end the feuding should be overshadowed by...