MARK JUDGE: Bad Blood on the Right: The Civil War Roiling Conservative Media.

Although often couched in complex political theory, conservative media’s internal war boils down to one idea: Some think it’s possible to work with liberals while others believe liberals are out to destroy conservatives and must be fought at every turn.

This divide explains the difference between a magazine like National Review, which sometimes but not always opposes President Trump’s populist policies, and pro-Trump outlets like American Greatness and the Federalist.

“National Review thinks we can make peace with the liberals in debates over principles and policies,” a conservative author, James Piereson, says. “But we can’t go too far lest they call us radicals. The other side thinks we are in a wartime situation: the left wants to destroy us. That is a large difference.”

The president of the William E. Simon Foundation, Mr. Piereson says that to understand the rift in conservative media, it helps to turn to a scene from “The Godfather.” In the film, after a rival faction tries to assassinate the head of the family one of its lawyers wants to make a peace deal.

As Mr. Piereson recalls, “The two brothers reply that you can’t make peace with people who are trying to kill you.”

He adds that there is “genuine bad blood” between the conservative journalists in New York and Washington, not that he’s taking sides.

Mr. Piereson observes that National Review “cares very much what the liberals think of them,” while the Federalist’s editor-in-chief, Mollie Hemingway, and American Greatness and others in that group “don’t care what they think because the left wants to eliminate opposition and take over. They also think the liberals have been pushed out of the conversation by the left, progressives, and ‘woke’ advocates to the point that liberals no longer exist — to the extent they do, they have come over to our side.”

One source who has more than a decade of experience both in conservative media and on Capitol Hill thinks that Mr. Pierson’s “Godfather” analogy is perfect — that disagreement stings harder when it’s coming from inside a political family.

“The difference boils down to this,” the source, who asked not to be identified for fear of upsetting friends and colleagues, says. “National Review thinks its job is to police the right. We think that our job is to defeat the left.”

Message to National Review: Never go against the family.