In the 1998 Clinton impeachment proceedings, only one legal scholar was called as a joint witness: Michael J. Gerhardt , now a Professor of Law at the University of North Carolina at Chapel Hill and a prolific expert on subjects of constitutional history, the legislative process, and impeachment. With the impeachment inquiry into President Donald Trump well underway, he recommends five books crucial to understanding the subject.

In the introduction to your concise, accessible and balanced book What Everyone Needs to Know about Impeachment, you write, “The first, and perhaps most important, thing that everyone needs to know about impeachment is that there is a lot to learn.” Let’s get started, beginning with the roots of the institution which Frank O. Bowman’s III traces back to England in High Crimes and Misdemeanors. Tell us about the book.

Read 1 High Crimes and Misdemeanors: A History of Impeachment for the Age of Trump by Frank O. Bowman III Read

Frank examines the British practice in detail, because the American system, set forth in the Constitution, was modeled on that to a significant degree. Understanding those origins helps to explain the terms used in the Constitution that set forth the grounds for impeachment, conviction, and removal.

Hoffer & Hull’s Impeachment in America takes us through the history of the institution from the seventeenth to nineteenth century. Why do you recommend this monograph?

Hoffer and Hull have written the best book on colonial impeachment (or impeachment-like) practices. These early practices in America provided models for the framers to consider and ultimately to use in fashioning the federal impeachment process.

Read 2 Impeachment in America by N. E. H. Hull & Peter Charles Hoffer Read

What does the early history of impeachment in America teach about the institution?

The history of impeachment helps to illuminate both the role of Congress in the process and the limits of presidential power. The framers vested the impeachment authority in Congress because they decided to vest that authority in politically accountable officials.

“More than anything else, the framers were concerned about a president’s corruption, including being disposed to tyranny”

More than anything else, the framers were concerned about a president’s corruption, including being disposed to tyranny. They designed the impeachment process as a check on presidential abuse of power but also divided it between the House and Senate as a safeguard against its being subject to abuse because of partisanship or factional influence.

Read 3 Constitutional Grounds for Presidential Impeachment by United States Congress Read

Constitutional Grounds for Presidential Impeachment is a publicly available report of the House Judiciary Committee from 1974. Why do you recommend it?

The House Judiciary Committee had a bi-partisan staff, which worked together, along with the historian C. Vann Woodward, to study the origins of impeachment in the United States. Their study is one of the best, most reliable, and comprehensive ever done. To this day, impeachment scholars cite the report with respect, and it is a great document to read to understand the history of impeachment at the federal level in this country.

The Power of Precedent was the title and topic of your 2011 Oxford University Press legal history. What do impeachment precedents teach us?

Prior impeachment proceedings provide useful guides for exercising the federal impeachment power. The House has impeached 19 people, and these impeachment proceedings in the House are helpful for understanding how the House understands its impeachment power. The impeachment trials of these impeached officials in the Senate demonstrate how hard it is to convict and remove someone; only eight of the nineteen have been convicted and removed from office. The requirement that two-thirds of the Senate present must agree on a conviction is a high bar to meet, as further reflected in how few people are actually convicted and removed in American history.

Read 4 Impeachment: The Constitutional Problems by Raoul Berger Read

The late Raoul Berger of Harvard Law School wrote Impeachment: The Constitutional Problems in 1974. Why do you recommend it?

Berger’s book was one of the first books, if not the first book, to take a serious look at the historical origins of impeachment, dating back to the early British practice. He examined all the major legal questions about impeachment. His study therefore provides another thoughtful analysis of the perennial questions that arise in impeachment proceedings.

Berger is personally credited with undermining the arguments of Nixon defenders. How did he do that?

Both in his book and his publications during the Nixon impeachment Berger shred the arguments of Nixon’s defenders. He demonstrated that they were not supported in the law of impeachment. He helped members of the House become confident that they had lawful grounds for impeaching the President of the United States.

Read 5 Impeachment: A Handbook by Charles L. Jr. Black Read

Yale Law School Professor Charles Black’s Impeachment: A Handbook is your next choice.

Black’s book is the best, concise explanation of the impeachment process. It is clear and insightful.

Does the present impeachment inquiry hew to this how-to guide?

It largely does. Black believed that structure was the important touchstone for understanding the Constitution, and structure is important to the impeachment process. First, the division of authority between the House and Senate is a “safeguard,” as Hamilton wrote, to ensuring there is proper deliberation over the matter.

“The impeachment trials of these impeached officials in the Senate demonstrate how hard it is to convict and remove someone”

The House may get the ball rolling, but the Senate wields the crucial decision-making power over conviction and removal. The two-thirds threshold for removal invariably works in favor of the impeached official; it is hard to satisfy this threshold, as reflected by the fact of the 19 people impeached by the House, only 8 have been convicted and removed from office. The two presidents thus far impeached (Johnson and Clinton) were both not convicted in the Senate.

Going back to What Everyone Needs to Know about Impeachment, which you published in 2018. In the book, aside from all the practical information you present, you ask whether the institution works. How have the events in the year since you published shed light on the question of impeachment’s effectiveness?

This is an important question that gets overlooked a lot. During Clinton’s impeachment and the impeachment proceedings conducted thus far against President Trump, we have seen how hard it is to find common ground any longer in impeachment proceedings. The pull of political parties has become so strong that it counts more to the people in Congress and perhaps the public as well than the law of impeachment. Along with the 24-7 news cycle, the defenders of the President have tried to confuse and distract people; they make no legally sound arguments but instead political talking points, which resonate with the President’s core constituents.

“As long as a president can keep his party unified in Congress, impeachment is practically impossible”

Given how hard it is for there to be a conviction in the Senate, we have to wonder whether impeachment is a meaningful check on presidential misconduct. As long as a president can keep his party unified in Congress, impeachment is practically impossible. That is not how the framers intended for the process to be, but it appears to be how the process has devolved over time. At present, we know what the President said and did, and we know it is clearly impeachable. Trump is not so much on trial as the American people are.