That was an instructive interview that Donald J. Trump agreed to this past weekend … wouldn’t you say?

“Meet the Press” host Chuck Todd asked the president to reveal his major regret since taking office. Trump said it was a “personnel” matter, specifically his decision to appoint Jeff Sessions to be attorney general.

My jaw dropped.

Todd asked, “Why?” Trump said it was because Sessions recused himself from the Russia investigation into alleged collusion with Russian operatives who attacked our electoral system.

Now, let’s ponder this for a moment.

Trump said his biggest mistake was hiring an AG who followed the law by recusing himself from a probe into an activity in which he — the AG — was involved. There was no way Sessions could investigate himself. So, he followed Justice Department policy by pulling away from the investigation, given that he was a key player in the campaign and in the transition to the presidency.

Sessions followed the law. Meanwhile, Trump appears to have no trouble with other Cabinet officials who were forced to resign because of ethical violations. Health and Human Services Secretary Tom Price quit because of travel violations; Interior Secretary Ryan Zinke resigned over similar accusations; same thing for Environmental Protection Agency administrator Scott Pruitt.

All that’s OK with Trump. Meanwhile, senior adviser Kellyanne Conway is accused of violating the Hatch Act by using her position as an executive branch official to launch partisan attacks against Trump opponents. That’s OK, too!

The president surrounds himself with scumbags and hangers-on and becomes enraged at a Cabinet officer who actually followed the law.

Good grief!

Jeff Sessions was a lousy choice to be AG for a lot of reasons. His decision to recuse himself from the Russia investigation, though, was not one of them. He merely revealed an understanding of the law and ethics that Donald Trump does not get.