This column has been updated.

Jonathan Turley is the chair of public interest law at George Washington University and served as the last lead counsel in an impeachment trial before the Senate in defense of Judge Thomas Porteous. He also serves as a legal analyst for both CBS and BBC.

The trial of President Trump starts this week, and there is no mistaking who is the architect of the defense: Trump himself. The White House declared that Trump’s calls and actions on the Ukrainian aid were “constitutional, perfectly legal, completely appropriate, and taken in furtherance of our national interest.” In other words, perfect. The call was perfect. The hold on aid was perfect. The eventual release of the aid after the whistleblower complaint was perfect.

In my December testimony to the House Judiciary Committee, I raised objections to the House rushing the impeachment forward on an incomplete and inferential case. There are ample defenses to be raised on both articles without claiming, implausibly, that this was handled perfectly.

This is probably why presidents and professors run in different circles. Where professors see this trial as a teachable moment, Trump sees it as a television moment. Trump knows television and may know his audience. He is staging a trial that portrays the impeachment as the equivalent of a drive-by shooting and himself as the victim. He knows that nuance can destroy such a narrative.

This defense is anything but nuanced. It appears premised on two highly contested points.

First, there is the position that there was nothing even remotely inappropriate in the president asking a foreign country to investigate a political rival. This position can be accepted or not accepted by senators.

However, the second point presents a far more difficult problem for senators concerned about the interpretation of the Constitution. The White House is arguing that you cannot impeach a president without a crime.

It is a view that is at odds with history and the purpose of the Constitution. While Framers did not want terms such as “maladministration” in the standard as dangerously too broad, they often spoke of impeachable conduct in noncriminal terms, such as Justice Joseph Story referring to “public wrongs,” “great offenses against the Constitution” or acts of “malfeasance or abuse of office.” Alexander Hamilton spoke of impeachment trials as addressing “the misconduct of public men, or, in other words, from the abuse or violation of some public trust.”

In the impeachment trials of Andrew Johnson and Bill Clinton, both sides accepted that the presidents had committed criminal acts.

In this impeachment, the House has decided to go forward on the narrowest articles with the thinnest record of a presidential impeachment in history. However, many senators may be legitimately leery of buying what the White House is selling with its categorical approach. There is a vast array of harmful and corrupt acts that a president can commit outside of the criminal code.

While I believe that articles of impeachment are ideally based on well-defined criminal conduct, I do not believe that the criminal code is the effective limit or scope of possible impeachable offenses. If some of the president’s critics are adopting a far too broad understanding of impeachable offenses, the White House is adopting a far too narrow one.

The adoption of this interpretation would create lasting harm for the constitutional system. In some ways, Republican senators should avoid the mistake made by Democratic senators during the Clinton impeachment. Clinton argued then that a president could commit criminal acts in office but not face impeachment so long as he committed the felonies for personal reasons. In my testimony roughly 20 years ago, I strongly opposed that theory and warned that, if perjury is allowed by presidents in some cases, “you will expand the space for executive conduct.” Indeed, the theory embraced by the Democrats would have allowed a President Harvey Weinstein to sexually harass dozens of interns in the White House and then lie about every incident to both Congress and an independent counsel. Yet, the Democrats signed off on the theory and thereby created a dangerous precedent for criminal, non-impeachable conduct.

The developing defense by the White House is also a mistake. It would again “expand the space for executive conduct” by reducing the definition of impeachable conduct to the criminal code. It is an argument that is as politically unwise as it is constitutionally shortsighted. There are a number of Democrats who might be willing to vote for acquittal, particularly on the highly flawed abuse of Congress article. Yet, the narrow White House definition of what is impeachable could well push them back into the Democratic fold while further pulling away a couple of moderate Republican senators.

Whatever benefit from the clarity of such a position will come at the cost of any possible consensus. If successful, it would also come at a considerable cost for the Constitution.

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