Rebecca:

I haven’t been down with talk of impeaching Donald Trump up to now. There were two reasons for this:

• Congress is held by Republicans. As a political matter, it’s highly unlikely, even improbable, that this Congress would impeach this president. Is there a line he could cross that would prove too much for Congressional Republicans? One hopes so, but one hasn’t actually seen sign of it.

• More importantly, I wasn’t convinced until this week that we had grounds for it. “I don’t like the president’s policies” isn’t good enough — elections have consequences — and the emoluments clause is vague enough for it not to get the traction it probably should.

But this week, the president fired the FBI director. Then gave implausible reasons for doing so. And it seemed the only plausible reason was that he didn’t like the FBI investigating whether Russia colluded with his presidential campaign.

Then, this morning, this happened:

Yes. That’s the president of the United States telling the former FBI director: “Shut up about what you know, or else I might have incriminating information about you.”

Does this meet the legal, chargeable definition of “blackmail” as a criminal offense? I don’t know. As a practical matter, it’s blackmail, the work of a thug done publicly.

The threat came on the heels of a number of stories, but here’s one I found particularly interesting:

As they ate, the president and Mr. Comey made small talk about the election and the crowd sizes at Mr. Trump’s rallies. The president then turned the conversation to whether Mr. Comey would pledge his loyalty to him.

By Mr. Comey’s account, his answer to Mr. Trump’s initial question apparently did not satisfy the president, the associates said. Later in the dinner, Mr. Trump again said to Mr. Comey that he needed his loyalty.

I think we have evidence that President Trump wants his cabinet members to subvert their oaths of office. Those oaths require a fidelity to the Constitution — not any single person within government. I’m not sure Donald Trump knows the difference between himself and the state he leads. I’m not sure he ever did.

All of which is to say: I still don’t think Republicans will impeach this president. But I’m starting to have a firmer sense of the grounds upon which an impeachment might be possible.

— Joel