The Bannon-Miller method has also produced the biggest mistakes of the first five weeks. The immigration executive order led to confusion around the world and defeat in court. The stonewalling over White House ties to Russia led to the resignation of national security adviser Michael Flynn and continuing investigations. The attacks on trading partners have required cabinet reassurance tours.

The central problem is that the Bannon agenda and style can’t produce the results they promise and may undermine the rest of Mr. Trump’s agenda. Tariffs that reduce trade won’t spur the growth Mr. Trump needs to lift incomes. A too-harsh crackdown on immigration will cause labor shortages that induce more U.S. production to move offshore, especially in agriculture. The attacks on the media may satisfy Mr. Trump’s core supporters, but they also create animosity and more political headwinds for his agenda.

All of this has begun to build incentives for Republicans to distance themselves from the White House, as Senate Republicans did when they abandoned Labor nominee Andy Puzder. Last week Rep. Darrell Issa called for a special prosecutor to investigate the White House Russian connection. Mr. Issa barely won re-election in California last year and he can see the progressive mobilization coming at him in 2018. The Bannon style is uniting Democrats and starting to divide Republicans.