The entire Trump presidency, then, now hangs in the balance of an unrestrained independent investigation, instigated by the president’s enemies, all because the president picked an AG who could have no role in the most important decision of the young administration.

Sessions said his recusal was required by regulations because he had been a campaign adviser and a Trump surrogate, and the ethics rules prohibit him from involvement in any investigations of the campaign.

With that knowledge, he and Trump should have re-thought his taking the job. But given Trump’s reported anger at Sessions for the recusal — he didn’t think it was necessary — it seems likely that Trump didn’t know about the rules and that they never discussed the implications of Sessions’ role in the campaign.