Ask most Republicans to identify Donald Trump’s biggest triumph to date, and the answer comes quick: Supreme Court Justice Neil Gorsuch. That’s the cramped view.

The media remains so caught up with the president’s tweets that it has missed Mr. Trump’s project to transform the rest of the federal judiciary. The president is stocking the courts with a class of brilliant young textualists bearing little relation to even their Reagan or Bush predecessors. Mr. Trump’s nastygrams to Bob Corker will be a distant memory next week....