White House adviser Kellyanne Conway. (Mark Wilson/Getty Images)

WHITE HOUSE counselor Kellyanne Conway is well-versed in long-standing ethics law that bars federal employees from engaging in partisan politics while on the job. Restrictions of the Hatch Act have been spelled out to her in formal training, individual conversations and multiple written communications by the Office of White House Counsel. She simply doesn’t care that she violates the law. “Blah, blah, blah. . . . Let me know when the jail sentence starts,” she quipped to a reporter. Even worse than her breathtaking arrogance is that the president she works for — and on whose behalf she regularly and belligerently violates the Hatch Act — cares even less about the rules.

President Trump made clear Friday that he had no intention of following the recommendation of a watchdog government agency that Ms. Conway be fired for her “egregious, notorious, and ongoing” Hatch Act violations. “I think she’s a terrific person. She’s a tremendous spokeswoman. She’s been loyal. She’s just a great person,” he said during an interview on Fox News in response to the findings of the Office of Special Counsel that called Ms. Conway a “repeat offender” of the Hatch Act. It detailed numerous instances in which she disparaged Democratic presidential candidates while speaking in her official capacity during television interviews and on social media.

Mr. Trump tried to argue that Ms. Conway was being unfairly singled out and her freedom of speech denied. But the rules that Special Counsel Henry J. Kerner seeks to enforce have been upheld by the Supreme Court and applied to officials in previous administrations. The only difference is that those administrations actually acknowledged mistakes and took corrective action. For example, the Obama administration prohibited Cabinet members from speaking at the 2016 Democratic National Convention after one Cabinet secretary had been cited in violation of the Hatch Act for endorsing Hillary Clinton during a television interview.

The Trump administration, by contrast, did nothing last year after Ms. Conway was found in violation of the Hatch Act when she argued in favor of the Republican candidate running in Alabama’s special election for Senate. No doubt that emboldened her serial trashing of Democratic candidates. And given Mr. Trump’s disdain for the norm and the premium he places on slavish devotion to him, it’s no surprise he didn’t fire Ms. Conway but instead rose to her defense.

Credit, though, to Mr. Kerner, who was appointed by Mr. Trump, for his clear-eyed examination of the issues and unprecedented recommendation to fire someone in such a high-profile position. Calling out Ms. Conway’s egregious behavior and the danger it poses serves as a rebuke not just of Ms. Conway’s actions but of the president as well.

“As a highly visible member of the administration, Ms. Conway’s violations, if left unpunished, send a message to all federal employees that they need not abide by the Hatch Act’s restrictions,” wrote Mr. Kerner. “Her actions erode the principal foundation of our democratic system — the rule of law.”