In fact, while Mr. Conway’s criticisms of the president have made him something of a cult figure among progressives and never-Trump conservatives, his voice has also created an internal moat of support around his wife.

If his motivation was ever to encourage her to leave an administration he despises, Mr. Conway so far has had the opposite effect, binding Ms. Conway more closely to the president and in particular his family members, who have come to see her as a more sympathetic figure because of it. Speaking to law enforcement agents in Kansas City, Mo., on Friday, the president singled out Ms. Conway for praise for her work on fighting the opioid epidemic, asking her to stand up and calling her a “very special person.”

For her part, Ms. Conway has told friends that she viewed Eric Trump’s tweet favorably, seeing it as motivated not by a desire to knife her husband, but to defend her in public. She has also made clear what she thinks of her husband’s criticism of her boss, telling The Washington Post in an interview last summer: “I think it’s disrespectful. I think it disrespects his wife.”