The mood is more somber in Act II, as Republicans ponder their choice. A solitary Hamlet-like Paul Ryan paces the stage in a torn doublet and laments the evil days that have fallen on his party; he is accompanied by a Joker (who looks a lot like Lindsey Graham) who tells him that Donald Trump is a “kook,” someone who is “not fit to run the country.” But after several long monologues, in which he rationalizes that “there is nothing either good or bad, but thinking makes it so,” the young Mr. Ryan decides that the election is a binary choice and he and other Republicans must go along. He wavers after Mr. Trump engages in what he calls a “textbook definition” of racism and is caught on tape bragging about sexually assaulting women. Other women come forward, but they are largely ignored. Republicans make the choice to stick with him and to everyone’s surprise, Donald Trump wins. (Exit Mr. Ryan and Joker stage left.)

Act III opens to a scene shortly after the inauguration. One after another, Republican leaders bow the knee to the newly enthroned Orange God King, who is surrounded by a motley court of misfits, sycophants and brigands. Even as Mr. Trump’s behavior becomes increasingly outrageous and often unhinged, the party’s grandees appease and flatter him. Courtiers, who come and go, repeatedly reassure him that he is winning. After all, he is giving them what they want: judges, tax cuts, deregulation and an end to Obamacare mandates. Enter Paul Ryan, who is better dressed and a much more cheerful character in this act. He is asked: What choice would Republicans now make?

“We already made that choice,” he said. “We’re with Trump.”

“That’s a choice we made at the beginning of the year. That’s a choice we made during the campaign, which is we merged our agendas.”

And this is the New Normal for Republicans: the surrender of the party now seems complete. When the president retweets racist videos from a British fascist group, Republican leaders simply ignore it. They have grown accustomed to the politics of rationalization and the moral compromises it demands. So, as President Trump’s lies become more flagrant, they shrug. His conflicts of interest generate little attention, his tweet-rages hardly a blink. Even as the special prosecutor’s noose appears to close around the president’s inner circle, party leaders mimic Mr. Trump’s denunciations of the investigation. Despite toxic polling, Republicans have fallen into line behind his tax plan, even though it threatens to explode the deficit. There are dissenting voices, who are quickly hustled offstage, but they leave behind haunting warnings.