You beat me to this one, but here’s TPM’s Josh Marshall making a very important distinction:

Now ‘Critical Legal Studies’ does derive some of its ideas from the Marxian tradition. But Cruz didn’t say there are some professors at Harvard who belong to a school of legal thought with a Marxian background. He said there were a dozen who “say they were Marxists who believed in the Communists overthrowing the United States government.”

That’s sedition.

The handful of people Cruz now says he was referring are Social Democrats, not communists. And there’s zero evidence any of them support overthrowing the government of the United States, let alone openly saying so, as Cruz claims. This isn’t the 1930s we’re talking about. This was back in 1990s.

But try explaining that to a wingnut like Cruz. To a wingnut like Cruz, Social Democrats, the Democratic Party (or “Democrat Party” in wingnutspeak), Communism, Nazism, Marxism, Fascism, and Maoism are all the same thing.