Chris Matthews’ job is to provide MSNBC’s audience with political insights. He's supposed to have a lot of them; after all, he spent his career in and around Washington, D.C., power centers. But his recent befuddlement over Sen. Bernie Sanders’ self-description as a democratic socialist revealed the limits of that experience. Apparently, Matthews is bafflingly ignorant of an idea that's played a key role in the last two Democratic presidential nominating contests.

After last Friday’s Democratic presidential debate, Matthews appeared on MSNBC to analyze the results. And apparently his big insight was that Sanders’ ascendance in presidential primary polls means that old-school communism is making a comeback. Matthews’ apparent fear that he might personally have been publicly executed “if Castro and the Reds had won the Cold War,” went viral. But what he said immediately afterward was even more self-indicting.

“I don't know what he means by ‘socialist,’” Matthews said of the Vermont senator. “One week, it's ‘Denmark. We’re going to be like Denmark.’” That would be “harmless,” Matthews admitted, because the Nordic state is “basically a capitalist country with a lot of good social welfare programs.” But Matthews insisted that Sanders might secretly have something far more dire in mind. When a fellow MSNBC host argued that the senator is “pretty clearly in the Denmark category,” Matthews replied: “Is he? Are you sure? How do you know? Did he tell you that?”

Matthews’ apparent uncertainty about Sanders’ definition of “democratic socialist” is bizarre. The Democratic presidential candidate has explained the term over and over in major venues for years. He’s devoted major speeches in each of his presidential campaigns to the topic. And he’s discussed it in interviews, during several prime-time presidential primary debates, and on the campaign trail. And while Matthews suggested that Sanders’ comparison to Denmark is somewhat new, Sanders has described “democratic socialism” in terms of a Scandanavian-style economy since at least his Senate election in 2006.

To Sanders, “democratic socialism” means treating economic rights, like access to health care, housing, and education, as human rights. Its mechanisms include expanding social welfare programs, increasing the minimum wage, and strengthening trade unions. It also requires reforming the political system to make it more attuned to the public and less influenced by the wealthy and powerful. The political thinkers he credits are not Marx and Lenin, but Franklin Delano Roosevelt and Martin Luther King Jr. 

Sanders hit all of those notes in a speech laying out “the path that I call democratic socialism” last June. “We must recognize that in the 21st century, in the wealthiest country in the history of the world, economic rights are human rights. That is what I mean by democratic socialism,” he said. “As Dr. Martin Luther King Jr. said, ‘Call it democracy, or call it democratic socialism, but there must be a better distribution of wealth within this country for all of God’s children.’”

It’s unclear what part of Sanders’ program Matthews disagrees with, if any. But Matthews’ ignorance has real consequences, especially for people who rely on his show for their political news. And some of Matthews’ programming decisions make that ignorance seem purposeful. When Sanders gave that address on June 12, Matthews basically skipped it.

Hours after Sanders spoke, Matthews hosted his campaign co-chair Nina Turner. But after introducing her and acknowledging that “Bernie gave a big speech,” he devoted the interview to the “bigger news” breaking about President Donald Trump. The next night, the speech itself again received short shrift -- rather than showing his audience what Sanders had said, Matthews instead aired a clip of a different Democratic presidential candidate criticizing it, before closing his broadcast with a monologue about socialism’s unpopularity and how Roosevelt was “not a socialist” that all but ignored Sanders’ actual argument.

Pundits can reasonably argue over whether Sanders’ vision is wise, or realistically achievable within the constraints of the U.S. system. They can mull over whether Sanders’ description actually comports with “socialism” as it is traditionally defined, discuss the degree to which Denmark’s system is actually “socialist,” and question how closely Sanders’ platform aligns the U.S. with Nordic countries.

But they can’t, as Chris Matthews does, both claim to be experts on politics and insist that Sanders’ views are a mystery.