“What’s relevant is [Steele’s] credibility, the reliability of his sources and the truthfulness of their claims,” Stephens wrote recently. “These check out.”

But do they? In reality, most reasonable people not named Mueller would have to say we don’t know.

“As it relates to the Steele dossier, unfortunately the committee has hit a wall,” Senate Intelligence Committee chairman Richard Burr noted last month. The committee’s investigation, the best probe outside of the Mueller special prosecutor operation, has not even been able to discover who Steele’s sources were, Burr said.

So how do outsiders conclude that the document’s key allegations check out? How do they know what they know?