In the three weeks since Robert Mueller’s report was released, House Democrats have remained divided about whether to impeach President Trump. Mueller wrote that he could not clear Trump of obstruction of justice but that, because of Justice Department policy, he could not prosecute Trump for it either. The conversation about impeachment, in turn, has tended to focus on whether Trump’s efforts to thwart investigations by the Justice Department and, more recently, Congress rise to a level that mandates impeachment. On Wednesday, the Speaker of the House, Nancy Pelosi, said that Trump is “becoming self-impeachable” because of his refusal to coöperate with House investigations.

But was the impeachment process designed to determine whether the President has committed a crime, or should it focus on broader questions about a President’s use or abuse of office? To discuss this question, I recently spoke by phone with Michael Gerhardt, a professor of constitutional law at the University of North Carolina at Chapel Hill and the author of “Impeachment: What Everyone Needs to Know” and “The Federal Impeachment Process.” During our conversation, which has been edited for length and clarity, we discussed why impeachment is about more than law-breaking, what previous impeachment proceedings did and did not accomplish, and what Mueller was trying to say to Congress in his report.

What do you think the post-Mueller debate around Trump and impeachment is capturing or failing to capture about the proper way to think about the subject?

I think that much of the public debate doesn’t understand impeachment properly. There are arguments made, positions taken, but they’re not really well tailored for the impeachment process.

One of the essential things about impeachment is that it does not have to be based on an actual criminal violation, and it does not have to track the elements in a federal criminal statute or state criminal statute. It’s perfectly well within the power of Congress, in particular the House, to frame impeachment on the basis of things that are not themselves criminal.

A lot of the discourse has been focussing on whether or not whatever the President did is actual criminal misconduct. Yes, a criminal statute violation, like perjury, for example, could be a basis for impeachment, but you don’t need the technical criminal violation. A President lying to the public—that could be a basis for impeachment. Or a President trying to interfere with an investigation. Those things could be understood as abuse of power, and they don’t have to be criminal.

It still seems like there’s a distinction that could be made. You could say that the way the President has behaved about Russia—everything from calling for Hillary Clinton’s e-mails to be hacked to firing James Comey or telling Don McGahn to fire Mueller—rises to the level of impeachment. Or you could say that Donald Trump, more generally, is acting like an immoral person and is lying to the American people. Forget Russia: he should be impeached because he is not fit to be President. Those seem like two different things to me, even though neither of them is necessarily based around a specific crime.

Well, I think you’re right to raise those two things. I think each of those, separately, could be a credible or permissible basis for impeachment. And it could also be argued that, if there were a technical violation of the criminal statute, such as obstruction, that could also be a basis for impeachment. The classic definition of impeachable offense would be a serious abuse of power or serious injury to the Republic. So those two examples you just gave me could be examples of one or the other.

If you go back to look at the Constitutional Convention, and the debate over the impeachment clause, the things that are mentioned are not technically criminal offenses. At one point, George Mason talks about how, if pardon power is used to help shield the President from a criminal investigation, that could be an impeachable offense. Again, it doesn’t have to be technically criminal, but it does sound bad. And I think most people agree that’s bad misconduct. That’s a bad use of the office of the Presidency. So, with respect to Trump and Putin, all of the ways in which the President has misled people, or not disclosed things, or abused power—any of those things could be basis for impeachment.

What have you made of the way that the House Speaker, Nancy Pelosi, has been talking about impeachment, essentially saying that we have an election coming up in a little more than a year, and this can be settled at the ballot box?

Impeachment is a political proceeding, and the framers vested this power in political authority, and therefore it’s consistent with the design of the process for political leaders to make political calculations on whether or not to impeach. The second related thing is that the fact that the House has the power to impeach doesn’t necessarily mean it will impeach or it should impeach. It has the discretion not to bring an impeachment, for whatever reason it comes up with. So all that could make sense.

Speaker Pelosi’s also said that, short of an impeachment process, Congress is entitled to investigate and even to lay a foundation through its investigation to later bring an impeachment. Congress is fully entitled, whichever party controls it, to investigate the person in the White House, for abuses of power, lying, or breaking laws.

Is there any history of Presidents facing impeachment or the prospect of impeachment from refusing to deal with Congress or comply with their investigatory demands?

One thing we learn from Watergate is that the coverup can often be worse than the crime. So even when there’s not an underlying crime—let’s say it’s just something embarrassing, then people seek to cover it up—that’s where the misconduct arises. That was part of Bill Clinton’s problem, and it could well be part of Donald Trump’s problem.

You said earlier that this is a political process. Because it’s a political process, does it bother you less when Pelosi kind of says that it would be better for Democrats not to impeach Trump? Or do you mean something different by “political”?

The political process clearly involves all the political leaders and members of Congress, and they will make calculations on the basis of politics as well as the Constitution. That’s part of what we get from the design of the impeachment process. I’m not critical of Speaker Pelosi when she says what you said. She’s also said, Look, the President has lied and some investigations are needed, and that’s a perfectly appropriate judgment.

The mix of political and constitutional is really a hard one to figure out sometimes. And the political judgment may in a sense outweigh the constitutional judgment or vice-versa, and the reason it might work out differently at different times is the political makeup of Congress. For example, if Democrats had control of the House and the Senate when Clinton was President, my guess is there would have been no impeachment.

Even if we acknowledge that one party controls the House and the other party controls the Senate, and there’s no chance of a conviction, do you think that there are certain things the President could do that would require the House to impeach him, even if it’s politically bad for them?