Over the past several weeks, I’ve been writing and talking a lot on this blog and in the popular media about technical legal stuff — emoluments, the application of obstruction of justice statutes in the special case of presidents, whether a president can pardon himself, whether Donald Trump, Jr. violated federal election laws by meeting with the Russians, the procedural hurdles that stand between Special Counsel Robert Mueller and indictment or impeachment, and the relatively limited power of state attorneys general to investigate a president.

In looking back, I find that a recurring theme has been that Trump’s opponents sometimes seem willing to stretch the the letter of the law or traditional expectations about proper governmental behavior in order get at Mr. Trump.  My task has often been to say, “No, the law can’t be read as elastically as you would like,” or “No, the aggressive action you want to see is not consistent with the role of prosecutors in America.”

To which those who see in Mr. Trump a mortal danger to democracy might reply, “Well, yes, possibly.  But Trump is an extraordinary threat requiring extraordinary measures. Musty old maxims about strictly construing penal statutes in favor of the defendant and antique conceptions of prosecutorial restraint shouldn’t bind us in the face of an existential threat.”

Indeed, at least a few of the comments posted on Slate and the Wall Street Journal essentially say, “This Bowman guy should just shut up if all he’s going to talk about is what can’t be done.”

I am sympathetic to the sentiment behind these reactions.  I yield to no one in my disapproval of Mr. Trump.  Better wordsmiths than I have worn out their thesauruses in search of language that would adequately describe his seemingly limitless personal defects and his utter unsuitability for the office he holds.

And yet…

Those who oppose Mr. Trump need to think very carefully about why they oppose him and about the remedies that are appropriate to the ground of their opposition.

First, it is undeniable that he can, and will, do a great deal of damage so long as he remains in office.  But much of what his most ardent opponents view as damage will come in the form of policies — legally enacted by statute or regulation — that may be anathema to liberals and even most moderates, but which are neither more nor less than the long-stated platform of the modern Republican Party.  However much one may disagree with the particulars of the Republican agenda, its enactment by constitutionally elected officials is not a constitutional crisis.

• Rejecting climate science is stupid and pulling out of the Paris climate accords is foolish, but neither choice offends the constitution.
• Tax cuts for the rich as the perennial solution for every ill may be lousy economics, but as Justice Holmes once observed, the constitution does not guarantee the ascendance of any particular social or economic theory.
• Building a “great border wall” is a comically ineffectual symbolic substitute for a real immigration policy, but, as much as the left may want to deny it, there are serious arguments for more restrictive and more selective immigration laws.
• Jeff Sessions (however long he may last) is dragging federal law enforcement back into the morass of excessive punitiveness that even most conservatives have begun to abandon, but in doing so he is only enforcing laws Congress has not seen fit to alter.
• Repealing or crippling the Affordable Care Act is both profoundly inhumane and (I venture to predict) terrible politics, but the country survived for over two centuries without the ACA, and the country will muddle along somehow if, despite this morning’s dramatic vote against “skinny repeal,” the Republicans nonetheless manage to mangle it.

I could go on, but the point is that the bad policy Mr. Trump and a Republican congress may enact is only that – bad policy.  For over two centuries the constitution has provided the institutional framework for enacting countless bad policies … and the framework for fixing many of them. The proper response to bad policy is democratic politics — not impeachment of the elected president who espouses it.  And, as has often been noted, removal of Mr. Trump merely puts Vice President Pence in the Oval Office, and Mr. Pence is, if anything, a more ardent and perhaps more competent exponent of extreme conservative policy positions.

Second, the very real danger Mr. Trump poses to the Republic stems primarily from his own peculiar persona, but even there his opponents should be cautious.  For example, many properly despise Mr. Trump for his boastful misogyny — at least outside the tiny circle of his own family he obviously views women as either sex toys or servants. But Democrats are poorly situated to find that attitude — or even conduct consistent with it — disqualifying in a president. On this score at least there is not much to choose between Bill Clinton and Donald Trump, or for that matter between Trump and other heroes of the liberal past like John Kennedy.  Indeed, on this score Mr. Trump comes off rather better than they in that, despite his crudity, he has not, so far as we know, turned the White House into his personal libidinous hunting ground.  And Democrats spent the late 1990s arguing that actual adulterous sex in the White House and perjury about the adultery is not disqualifying in a president.

Many of Mr. Trump’s other manifest personal defects are not without presidential precedent. Those old enough will recall Lyndon Johnson’s petty cruelties like the repeated humiliation of Vice President Hubert Humphrey.  Woodrow Wilson was a candid racist, and even an otherwise pretty decent guy like the first President Bush was not above fanning racial insecurities to win an election. Trump’s happy ignorance of science and economics will be sadly familiar to anyone who lived through the Reagan years, and his blithe disregard of facts as a guide to policy making finds a recent echo in the second President Bush’s decision to invade Iraq.

One might fairly respond that Trump is different because, although each of his predecessors had unsavory traits, he embodies in a single man virtually all the undesirable characteristics of many presidential generations, with virtually none of their virtues.  And he carries some common presidential weaknesses, like lying, to previously unimaginable extremes.  I would be hard pressed to disagree.  Yet the sad truth is none of Mr. Trump’s traits was a secret before the election.  America knew who he was, and elected him anyway.  Being a miserable human being is not an impeachable offense.

A president should only be impeached if his continuation in office represents a genuine threat to the security of the country or the constitutional order.  That said, any reasonable observer must have concerns about Mr. Trump on both grounds.

He is proudly ignorant and — regardless of whether he fits into diagnostic criteria for mental illness — impetuous, vindictive, and unstable.  Having such a person at the helm of a world hyperpower is deeply dangerous to the security of the United States and the peace of the world.  But it is unclear how a duly elected president can be removed for being psychologically unfit for the job.  The 25th Amendment might technically apply, but triggering it would require the assent of the majority of the cabinet Trump himself appointed.  Perhaps personal instability is impeachable, but at least if we take constitutional language and limited precedent seriously, impeachment for a “high crime or misdemeanor” would seem to require some consequential presidential act manifesting the fundamental instability.  I will return to this point in later posts.

But the main thrust of today’s epistle is that the most likely and constitutionally supportable grounds for impeachment of Mr. Trump will arise from behavior that violates the law or disregards the unwritten standards of conduct  — which lawyers and philosophers and social science types give the fancy name “norms” –without which the rule of law cannot function.

It is because I believe Mr. Trump threatens the rule of law that I started to write this blog.  My fear does not – so far -center on concern that Mr. Trump will act in direct defiance of plain legal rules.  It arises from daily observation of his incessant and accelerating attacks on the unwritten norms that keep the legal and political process honest and make the rules work.

• No law requires disclosure of presidential tax returns or divestment of presidential assets, but the obvious virtue of preventing conflicts of interest in the nation’s highest official has, until Trump, made disclosure and divestment (or management in blind trusts) the universal norm.
• No law, with the debatable exception of the emoluments clauses, requires that a president refrain from blatant profiteering off of his official position, but the obvious taint of corruption that attaches to such behavior has meant that, until Trump, the emoluments clauses have never in over two centuries been a live issue.
• No law requires a president to be scrupulously honest all the time, but the obvious benefit of enjoying credibility with the public, the courts, political friends and adversaries, has, until Trump, meant that presidents try hard to tell the truth most of the time and don’t lie to everyone, every day, about so many subjects that the chief executive’s word becomes effectively worthless.
• No law bars a newly-elected president from urging the criminal prosecution of his defeated opponent, but the obvious danger of transforming a democratic state into a tyrannical banana republic has, until Trump, put such vindictiveness beyond serious contemplation.
• No law requires that presidents scrupulously avoid direct intervention in federal criminal investigations, but the obvious virtue of avoiding even the appearance that a president is shielding himself or his friends, or using the criminal law to persecute political enemies, has made Justice Department independence a norm presidents challenge at their peril.

It is Mr. Trump’s violation of these and an ever-growing host of other norms that makes him dangerous.  A violator of law can be punished by the courts and the sanctity of law thus upheld. Norms are different.  However sacred we may thoughtlessly have assumed them to be, violating them incurs no necessary sanction, certainly none that can be enforced by courts and bailiffs.  Nonetheless, if norms are disregarded with impunity, then they lose all effect.  How then ought we to respond to Mr. Trumps unremitting assault on the norms of civil society?

Norms are enforced informally, through communal disapproval, which in politics most commonly translates into electoral defeat.  In extreme cases, sufficiently egregious violations of core democratic norms may properly trigger the constitution’s impeachment remedy and allow an injured nation to remove an offender before his term expires.  I plan to talk a lot in coming weeks and months about how Mr. Trump’s violations of democratic norms may qualify as impeachable offenses.

But those who would impeach a president for his disregard of democratic norms must come to the task with clean hands. It will not do to say that, because Trump flaunts some norms, other norms can justifiably be bent or broken to bring him low. If that becomes the stance of Trump’s pursuers, then they become little better than the object of their indignation, and what should be a righteous pursuit will seem no more than partisan vindictiveness. Which will degrade the very standards of conduct we should all be seeking to uphold, and lead, inevitably, to yet another round of bitter political warfare conducted with even fewer restraints and less decency.

If that happens, those who oppose Mr. Trump will have failed utterly, even if they succeed in expelling him from office.

If Mr. Trump is to be removed, it must be for reasons and employing procedures to which there can be no fair-minded objection. To paraphrase a rather more admirable public figure from what already seems an antique golden era, “However low he may go, we must stay high.”