How does impeachment work exactly? If only there were some sort of handbook ...

Turns out, there is.

Impeachment: A Handbook began as an essay of about 60 pages, written by Charles L. Black Jr. in 1974. President Richard Nixon's impeachment was heating up, and Black was a law professor (first at Columbia, then at Yale), who saw the need for a clear piece on the subject.

The House of Representatives votes Wednesday on two articles of impeachment against President Donald Trump. At a time when every day, every hearing, every vote is described in the news as "momentous," it can be hard to follow along with any sense of perspective. Books help — and so we turned to Black's handbook to see what we could learn.

There is a lot of literature about the process, but much of it is written with the purpose of impeaching or defending a specific person, says Benjamin Wittes of the blog Lawfare. There are fewer examples of truly objective texts. Impeachment: A Handbook is not only that, but "a pleasure to read," says Wittes.

Black, who died in 2001, had helped Thurgood Marshall write the legal brief for Brown v. Board of Education. "He was just a very unusual guy," recalls Philip Bobbitt, a colleague of Black's who co-wrote the newest edition. He "was a poet of considerable distinction, he played the trumpet; he appears in the Ken Burns documentary on jazz."

A 2018 edition of the book pairs Black's essay with a new one written by Bobbitt, who recalls seeing Black's original become a "kind of bible for impeachment studies" carried around by staffers on Capitol Hill "whenever there was an impeachment rumor."

Enthusiasm for the essay among legal scholars has not waned (an edition also came out in 1998 when President Bill Clinton was impeached). Lawfare posted an entire chapter online in 2017. So what explains the book's staying power? Both Bobbitt and Wittes say it is the clarity of Black's writing — the way he makes and dismantles arguments so easily, in language you don't need to be a legal scholar to understand.

Black never pushes for an impeachment, although he makes it clear he was no fan of Richard Nixon. Instead, says Wittes, "in the midst of Watergate, when passions were really high, he said, let's be cool. Let's cool it down and think about how to do this in a sober way. It is a majestic little piece of thought."

The book clears up misconceptions about impeachment — for example, defining what might count as an impeachable offense, noting that it doesn't necessarily have to be a crime:

Wittes calls the passage "the most beautiful rebuttal to the notion that the impeachable offense has to be a criminal act ... He just dismantles it in this very elegant, single anecdote."

Impeachment: A Handbook also lays out the nuts and bolts of the process. After today's vote in the House, the Senate will hold what amounts to a trial. Senators take a special oath of office to be impartial during that trial. "Here," writes Black, "a difficulty arises." A normal jury would be asked questions about their prejudices and their backgrounds, and then they'd be chosen or rejected based on what they said. But that's obviously impossible to do with Senators, who are already in place.

So, Black argues "the remedy has to be in the conscience of each senator, who ought to realize the danger and try as far as possible to divest himself of all prejudice. I see no reason why this cannot produce a satisfactory result."

The book leans hard on lawmakers to be people of conscience. "In fact, if the book has an overarching theme, that is it," says Wittes.

He notes that Senate Majority Leader Mitch McConnell has already seemed to imply that he would not listen impartially to the evidence presented at the upcoming Senate trial. McConnell told Fox News's Sean Hannity: "Everything I do during this, I'm coordinating with the White House counsel. There will be no difference between the president's position and our position as to how to handle this to the extent that we can."

Senators face a number of different pressures throughout this process. "They may look instead to the next election," Bobbitt says. "They may be terrified of criticism from their own party, whether it's the Democratic Party or the Republican Party. All those things are true, but all those things beset us in everyday life anyway, we are always buffeted by pressures of one kind or another."

The book makes it clear that impeachment is an opportunity for lawmakers — and citizens — to look inward.

"Impeachment is a matter of law," says Bobbitt, "but the most difficult questions of law always in the end turn back to the individual conscience in this country, in this Constitution. And that's where it should be."

Tom Cole edited this story.

Copyright 2023 NPR. To see more, visit https://www.npr.org.