To understand the dance of death in Washington now between Donald Trump, Robert Mueller and the media, you need to watch the first 10 minutes of “The Wild Bunch,” Sam Peckinpah’s classic movie of the Old West.

It shows a trapped scorpion struggling in the dirt as it fights off hundreds of ants. A group of children are watching the scorpion fight the ants, and sometimes they poke it with a stick.

In...