Susan Glasser notes that the Mueller investigation owns Trump’s attention.

Given the constant, repetitive nature of Trump’s “witch hunt” tweets, it might be tempting to ignore them. That would be a mistake. The chief executive’s attention is the most valuable resource of any Administration—what a President spends his time on reflects, more than anything else, an Administration’s true priorities. By those standards, the “witch hunt” is the overriding priority of the Trump White House, and it will be even more so in the new year, when the special counsel, Robert Mueller, moves toward a conclusion and a new, Democratic-controlled House of Representatives, with the power and the votes to subpoena and impeach Trump, takes office.

So, given the fact of Trump’s occupation of the White House, that’s a good thing. Time Trump spends tweeting “WITCH HUNT!!” and its cognates is time he doesn’t spend tearing up environmental laws or begging the North Koreans to stay in his hotels.

Largely overlooked in the daily flood of Trump-era news, a week ago, his former Secretary of State, Rex Tillerson, said in an interview that Trump had repeatedly pressed him to violate the law. “I’d have to say to him, ‘Mr. President, I understand what you wanna do, but you can’t do it that way. It violates the law, it violates treaty.’ He got really frustrated,” Tillerson said. “I think he grew tired of me being the guy who told him, ‘You can’t do that.’ ”

Trump’s insults in response drew attention away from the substance, but that won’t last.

Tillerson’s allegation was more than just another bout of Trump-era name-calling between a former Secretary of State who once called his boss a “fucking moron” and the President who fired him by tweet. Imagine Tillerson before Congress come January, testifying under oath and live on television, about which laws Trump told him to break.

Oh yes; imagine that. How interesting it will be.