This week I was asked by a professional contact in the history community to add my name to this statement, called the Historians’ Statement on the Impeachment of President Trump. It was an easy call for me to do so. But, as has become evident over the last few days, this statement was much more than just another “online petition.” The historians who have signed this statement, now more than 2,000 of them, have had a measurable impact on the events that occurred in Washington, D.C. this week. Indeed, Speaker of the House Nancy Pelosi referenced the statement in her floor speech beginning debate on the impeachment of Trump. As you know, the House of Representatives voted to impeach him. We historians have joined numerous other professionals whose expertise is relevant to the impeachment process, such as Constitutional legal scholars and public prosecutors, in stating that impeachment is warranted under the standards of the Constitution.

Some of the historians I joined in signing include Ken Burns (documentary historian), Robert Caro (biographer of LBJ), Ron Chernow (author of the biography of Alexander Hamilton that was the basis of the Broadway musical), John Fea (fellow history podcaster and author of the wonderful Way of Improvement Leads Home blog), Alan Taylor (Pulitzer Prize winning historian), Matthew Dennis (my former academic advisor), and many, many more.

While the statement speaks for itself, I thought I would add a few words to explain why I signed it.

I marched in favor of women’s rights and solidarity on the day after President Trump was inaugurated in 2017. That action was political. My signing of the Historians’ Statement goes beyond politics.

Reason one: Trump’s actions are unquestionably impeachable.

The Constitution’s standard for impeachment is deliberately vague: “Treason, Bribery, or other high Crimes and Misdemeanors.” The fact that it’s vague doesn’t mean it’s always difficult to tell when the standard has been reached. The impeachment inquiry has proven beyond all doubt that Trump committed bribery by conditioning aid to the government of Ukraine on their investigation of the Biden family. That’s bribery. As for other “high Crimes and Misdemeanors,” it seems difficult to argue that this standard hasn’t been reached either. If we could go back in time to the stuffy room in Philadelphia where the Founders met in the summer of 1787 to create the Constitution and give them the example of Trump’s actions, it’s abundantly clear that they would agree, probably to a man, that this is the kind of behavior they had in mind when they wrote the impeachment clause. The evidence is uncontroverted. I say that both as a historian and as a lawyer.

Reason two: The Constitution and its processes must be protected.

America was created with the notion that the Constitution is the supreme law of the land. Flawed, yes; imperfect, yes; subject to change in interpretation by future generations who are entrusted with it, certainly. But some things about it are absolute. If the Constitution’s standard for a President’s removal from office is reached, not taking the Constitutionally-required action to set that process in motion does violence to the primacy of the Constitution and its principles. Letting Trump’s unconscionable behavior slide, giving it a pass, is itself an affront to the Constitution and everything it stands for.

The action of impeachment entails considerable political risk. While it’s true that I voted for the other lady (you know, the one who got more votes than Trump did), I’m certainly not happy with the idea that, if Trump were to be convicted, his successor would be Mike Pence, a man whose bedrock principle is that I, as a member of the LGBT community, do not deserve basic human and civil rights, and once in office he’ll likely mobilize the power of the government to strip me of those rights–because he’s done it before. But that’s a political calculation. The risk to the Constitution in turning a blind eye to Trump’s crimes transcends politics, and it should. That’s what the primacy of the Constitution means.

The men who met in this room in the summer of 1787 believed they were serving principles larger than themselves. I think we have to honor that commitment, however imperfect the Constitution was (and still is).

Reason three: Trump must be taught that his wrong actions have consequences.

Even if the Senate takes the cowardly way out and does not convict him, the impeachment of Trump has considerable value on its own. One of them is to teach him something he apparently hasn’t learned during his nearly two years in office: he can’t just do anything he wants, and his bad actions have consequences. Apparently, he has learned that lesson. There is a report out of the White House this week that Trump was surprised, astonished and furious that he was impeached, and that he’s gone through violent mood swings as a result. Indeed, an aide is quoted as saying, “He’s very angry. It’s made a deep impression.” Trump is a man impervious to facts (such as the proven scientific reality of human-caused climate change) and incapable of empathy (such as when he ordered children to be placed in concentration camps). But if impeachment can get through to him on such a deep level, and tell him that his actions will receive push-back, from the Constitution if from no other source, then the impeachment is worth it on that score alone.

Reason four: Historical precedent shows that impeachment has the effect of reining in a wayward President’s actions.

If you look back at the two Presidents who have previously been impeached, Andrew Johnson in 1868 and Bill Clinton in 1998, you’ll see that, although neither was removed from office, impeachment had a profound effect on both of them: they took care to stop doing the actions that got them impeached in the first place. Andrew Johnson in particular was every bit as pugnacious and defiant about his impeachment as Trump is about his own. Yet, after the impeachment and Senate trial in May 1868, Johnson suddenly went quiet: he stopped trying to interfere with the Congress’s power over Reconstruction and he took no significant action for the rest of his term. Clinton, similarly, toned down his act in his last two years in office. And you can bet that, at long last, for once in his life, he stopped running around with young women and lying about it. Both Andrew Johnson and Bill Clinton were/are deeply flawed men who did monstrous things. But impeachment did put brakes on their reckless behavior. Even as defiant and vengeful as Trump is, I seriously doubt he’ll ever call up a head of state and ask them to interfere in our elections again. And there’s no telling what other more subtle effects it will have that can serve the public good.

Andrew Johnson was, like Trump, a racist man, a white supremacist, and deeply incompetent at his job as President of the United States. But, his impeachment in 1868 did have an effect on his behavior.

I don’t like to see our Constitutional system tested and tarnished by the actions of President Trump. Our government has many important things that it could be doing right now, like taking immediate and drastic action on climate change. But the Constitution must be protected, and sometimes its enemies are within the walls rather than without. I stand by the Historians’ Statement. I only hope it’s not too late for our republic to be saved from the damage being done to it by self-serving people like Donald J. Trump.

All images in this article were either taken by me or are in the public domain.