No. 2: It does not have bipartisan support. To this point, the former Acting Solicitor General Walter Dellinger observed on Twitter that Mr. Starr, one of his former students, “assumes that is a criticism of Democrats who have proceeded alone rather than of the GOP members who have refused to consider joining in a serious critique of the president’s actions.”

No. 3: The process was so flawed as to be illegitimate and a danger to the Republic. This has been the Republicans’ claim from the start, and it is no more valid today than when this process began.

The main lesson of Mr. Starr’s presentation: Irony is dead.

Equally riveting was the presentation by Jane Raskin, whose job was to argue that Rudy Giuliani, Mr. Trump’s personal lawyer and linchpin of the whole scheme, is a misunderstood patriot whom Democrats are scapegoating as a “colorful distraction” from the weakness of their case.

Uh, no. He’s colorful, all right, but he’s nobody’s fall guy.

Mr. Giuliani earns some ink in Mr. Bolton’s book. According to the Times account, Mr. Bolton writes in his manuscript that Secretary of State Mike Pompeo admitted to him last spring that Mr. Giuliani’s smear campaign against Marie Yovanovitch, who was the American ambassador to Ukraine, was unfounded. Mr. Bolton also writes that he shared his concerns with White House lawyers last year that Mr. Giuliani was leveraging his work for the president to benefit his other private clients. Mr. Bolton, you will recall from the House hearings, once referred to Mr. Giuliani as “a hand grenade who’s going to blow everybody up.”

Later in the afternoon Monday, it fell to Pam Bondi, the former Republican attorney general of Florida, to shift attention to the work done and the money made in Ukraine by Hunter Biden, the son of former Vice President Joe Biden.

And so the defense plowed on, even as the smoke from the Bolton bombshell hung over the chamber.

All of this is enough to make a Republican senator wonder how many other shoes are yet to drop.

Worse still, from lawmakers’ standpoint, multiple people within the White House have known about Mr. Bolton’s revelation since December, when he submitted a manuscript for prepublication review, as required. This means that senior White House officials knew full well on Saturday that the basis for much of the argument that day by the president’s defense lawyers was false and the evidence was destined to become public soon.