On the morning of January 6th, news networks confirmed that the Democrats had captured Georgia’s Senate seats, insuring that the Party will hold a majority in both houses of Congress once Joe Biden and Kamala Harris are inaugurated, next week, and giving the new Administration greater ability to carry out its agenda. That afternoon, a mob incited by President Trump ransacked the Capitol; in response, House leaders prepared to impeach the President for a second time, adopting a single article of incitement of insurrection. Ten Republicans joined the Democrats in voting for impeachment, among them Liz Cheney, the third-ranking House Republican and the daughter of former Vice-President Dick Cheney. Some Republican senators, including Senate Majority Leader Mitch McConnell, have indicated that they would consider voting for removal. However, McConnell, who will remain Majority Leader until the Georgia Democrats are seated, likely next week, has said that he will not begin the Senate impeachment trial until January 19th, the day before the Inauguration. Meanwhile, law-enforcement agencies have warned about the threat of further terrorist violence in Washington, D.C. before and on Inauguration Day.

The chaos and criminality of January 6th thus threaten to cast a shadow over Biden’s agenda, as well as to take up precious time on the congressional calendar. The last President to confront such problems concerning the culpability of a predecessor was Gerald Ford, who, shortly after taking office, in 1974, pardoned Richard Nixon for any and all crimes committed during Nixon’s Presidency. To talk about the wide-ranging effects of the pardon, I spoke by phone with the historian Rick Perlstein, who is the author of a series of books that chart the rise of modern conservatism. During our conversation, which has been edited for length and clarity, we also discussed Ford’s motives for pardoning Nixon, whether liberals should care about the health of the G.O.P., and why the Trump siege may have been the culmination of the Goldwater revolution.

Your work presents Ford taking office as this incredible unifying moment, or what people believed to be a unifying moment, which was then quickly shattered by the pardon. What lessons does it hold for today?

He takes the oath of office, and he says, “Our long national nightmare is over. Our Constitution works. Our great republic is a government of laws and not men.” The refrain across the land was, “The system works.” This great purgation had happened. And then it was only a month into his term when he went on TV, on a Sunday, after going to church, and granted a “full, free, and absolute pardon unto Richard Nixon for all offenses against the United States, which he, Richard Nixon, committed or may have committed or taken part in during the period from January 20th, 1969, through August 9th, 1974.” So if it had been discovered that Nixon shot someone in an alley off Fifth Avenue on one fine summer day in 1970, he wouldn’t go to jail for it. Of course, famously, Carl Bernstein called Bob Woodward and said, “The son of a bitch pardoned the son of a bitch.” That really seemed to express a pretty widespread national sentiment, as Ford’s approval rating dropped from seventy-one per cent to forty-nine per cent.

How do you understand Ford’s decision?

He had been given a legal opinion by one of his advisers that a pardon was tantamount to a full confession, and that gave him room to say that he had actually, indeed, called Nixon to account. But I guess you could call that his alibi. A big part of his thinking was that a trial of a former President would be very—and this is a key word in our current context—“divisive,” and disruptive, and that it would, to use one of the public-relations clichés that we live with now, kind of take up all the oxygen. That was pretty much it. There wasn’t any particular hidden agenda in it.