But you don’t judge the morality of an action by whether it succeeds. Franklin Roosevelt’s effort to pack the Supreme Court backfired. So did Richard Nixon’s effort to suppress the Watergate investigation. So did Bill Clinton’s decision to lie about his affair with Monica Lewinsky. What each man did was still wrong.

FBI Directors are supposed to investigate potential violations of the law even when those investigations cause political harm to the president under whom they serve.

That’s why presidents have fired FBI directors for only the most egregious misconduct and have avoided even the appearance of doing so to shield themselves from legal scrutiny. Trump has now violated that norm. Even if you believe Comey mishandled the investigation into Hillary Clinton’s emails, Trump’s claim that he fired Comey for that reason is preposterous given that Trump and his attorney general praised Comey’s behavior at the time.

We can only speculate about Trump’s true motivations. Maybe Trump was afraid Comey would expose collusion between his advisors and Russian agents. Maybe he was afraid Comey would find that he had violated the law in his business affairs. Maybe, as The New York Times reports, he was bitter that Comey had not supported his claims that President Obama wiretapped him. And we can only speculate about the outcome of Trump’s action. Maybe it will lead to a special prosecutor, thus ensuring that Trump’s Russia ties receive even more scrutiny.

But at some level, all this is beside the point. Since he launched his presidential campaign, Donald Trump has sought again and again to undermine the institutions charged with ensuring that he serves the public interest and obeys the law. He has threatened criminal prosecutions against the publishers of newspapers that report on him critically. He has attacked federal judges who render decisions about his business practices or his immigration policies. His Environmental Protection Agency chief has fired scientists who are supposed to offer impartial advice about environmental policy. And Trump has now fired three officials—Comey, acting attorney general Sally Yates and US Attorney Preet Bharara—who were investigating people close to him.

At the end of its editorial defending Comey’s firing, the Wall Street Journal argued that “a new FBI Director who looks at the Russia evidence with fresh eyes and without the political baggage of the last year will have a better chance of being credible to the American people. Mr. Trump should now devote himself to nominating someone of integrity who can meet that standard.”

This is cynicism masquerading as naivete. FBI Directors don’t enjoy public credibility only, or even mostly, because of their personal integrity. They enjoy public credibility because the job itself is insulated from political pressure. Trump has now violated that norm. And in so doing, he’s changed the nature of the job. Whoever Trump chooses will know he’s at risk of being fired if he investigates Trump too aggressively. And a future president will have Trump’s action as a precedent if she wants to fire an FBI director for causing her political harm.

For conservatives, Trump poses a test. What do they value more: defending a president whose policy agenda they generally support or defending the norms that preserve liberal democracy. The Wall Street Journal editorial page is not failing that test as brazenly as Sean Hannity. But it’s failing nonetheless.

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