In the fall of 1979, I took my first legal job. By astounding good fortune, I was hired fresh out of law school as a Trial Attorney in the Criminal Division of the U.S. Department of Justice in Washington, D.C. From the moment I first walked into the monumental neoclassical Main Justice Building on Pennsylvania Avenue, I knew that I’d come to a unique place.  The marble, the statuary, the New Deal-era murals, the glorious main library’s vaulted ceilings, gleaming oak, and book-laden shelves, and the pervasive air of deliberative rectitude and high seriousness enthralled me.

To be honest, I wasn’t a particularly good prosecutor to start with.  I was too young, too immature, too undisciplined.  But if I didn’t give the Justice Department all it deserved at the beginning of my career, it placed an indelible stamp on me.  During two tours with the Department, in which I served under Presidents Carter, Reagan, Bush Sr., and Clinton, I shed most of my initial gauzily romantic infatuation.  But in its place grew a deep appreciation of the central role the Justice Department plays in maintaining the rule of law in a democratic state and a hardnosed set of convictions about the values that must inform the Department’s work if republican government is to survive in America.

Mr. Trump and the congressional Republican Party are on the brink of grievously wounding the Department of Justice. If they succeed, they will have weakened, perhaps permanently, a pillar of American constitutionalism and one of its most important bulwarks against creeping autocracy.  Let me explain:

The U.S. Department of Justice is immensely powerful.  Neither its reach nor its resources are infinite.  But as to any individual, group, or corporation it elects to pursue, it can bring to bear nearly unlimited money, dedicated staff, and first-rank legal talent. Those lawyers are empowered to direct the immense resources of multiple federal law enforcement agencies — FBI, DEA, ATF, Secret Service, Customs, ICE, postal inspectors, and more. In appropriate cases, they can deploy investigators and experts from federal regulatory agencies like the SEC, the EPA, OSHA, and the FDA, and even in certain circumstances, military and intelligence assets.  Only Justice Department prosecutors can command the unmatched coercive powers of a federal grand jury.  Only federal prosecutors have the luxury of selecting criminal charges from the sprawling federal code, a body of law so all-encompassing that it is only slightly facetious to suggest that it criminalizes some aspect of virtually every human activity.  And the Department’s long arm can reach into every state and across oceans.

Some observers are understandably leery of DOJ’s immense power. But in the modern world, this power is essential. Without it, there would be no authority capable of combating organized crime, international criminal cartels, domestic terrorism, entrenched federal, state, and local political corruption, or complex financial fraud.  Without the Department of Justice, there would be no effective public counterweight to the staggering wealth and sometimes pernicious influence of modern multinational corporations.  The private centers of power Teddy Roosevelt labeled “malefactors of great wealth” have in our day metastasized to a degree T.R. could not have imagined.  Without DOJ, they would be unchecked.

With the power to combat great evil necessarily comes the power to inflict great harm. Conviction of a federal crime can mean imprisonment, impoverishment, even death.  Its collateral consequences can include public stigma, loss of livelihood, and destruction of family.  Even the wealthiest corporations – Enron and Arthur Andersen, to name but two – can be destroyed.  Just being investigated by DOJ can inflict a steep price in time, money, and sullied reputation.

Power this crushing is only tolerable in a free society if it is exercised — and generally believed to be exercised — impartially, humanely, and in the interests of justice in the broadest and best sense. My youthful infatuation with the Department, and my lifelong affection for it, rests on the conviction that, with occasional exceptions inevitable in any human institution, the men and women of the Department, both career public servants and political appointees, are conscious of their grave responsibility and strive to wield their power impartially and with honor.  Critically, the Department’s people have fiercely resisted pressure to ignore the crimes of officeholders and their friends, or to transform the sword of criminal justice into a weapon against the political opponents of the sitting president.  Because of this tradition long upheld, the Department’s prosecutors enjoy a reputation for professional probity every bit as central to their success as the raw institutional power at their disposal.

It is by now obvious that Mr. Trump cares nothing about the institutional integrity of the Justice Department, and has actively tried to corrupt it.  He tried to convince FBI Director James Comey not to investigate presidential adviser Michael Flynn, and then fired Comey when the Director wouldn’t take the hint. He fulminates nearly daily about Robert Mueller’s investigation of Russian election interference and flirts publicly with obstructive maneuvers like firing Mueller, firing Attorney General Sessions, or pardoning everyone involved in the case. And recently he has tried to pressure the Department into investigating a series of long-resolved or self-evidently bogus allegations against his former opponent Hillary Clinton and other Democrats.

Trump’s effort to strong-arm the Department into abandoning its most basic values by initiating baseless, politically motivated investigations is distressing enough.  I have argued previously that it constitutes an impeachable offense. But one could (almost) dismiss Trump’s tweets and barks on this subject as yet another instance of his singular misunderstanding of American government.  And one could be comforted by the likelihood that his outbursts would be rendered ineffectual by the resistance they would surely encounter from others in government with a better sense of constitutional norms.

The Republicans on the House Judiciary Committee have now stripped away that comfort.  In late July, seventeen Republican committee members sent a letter to Jeff Sessions demanding that the Justice Department investigate a grab-bag of spurious charges against Secretary Clinton and others.  During Attorney General Sessions’ appearance before the committee earlier this week, Republican members hammered ceaselessly on their demand for a new special prosecutor to investigate Secretary Clinton, with special emphasis on long-since debunked claims about the so-called “Uranium One” affair.  Sessions has yielded at least so far as to assign “senior federal prosecutors” to assess the Republicans’ requests.

I am not sure people understand how shatteringly consequential this is.  It is bad enough to have Mr. Trump – whom, sadly, no one now expects to understand democratic norms — seek to weaponize the Department of Justice.  But what we have witnessed in the months leading up to the Sessions hearing is the utter moral degradation of House Republicans. Seventeen Republican congressmen, virtually all lawyers, many of them former prosecutors, specially selected by their party to sit on a Committee dedicated to ensuring the integrity of the American justice system, are demanding that the Justice Department investigate a list of allegations almost every one of which is obviously either legally or factually baseless. And the Republicans know it.  No sentient lawyer could think otherwise.

The game here is obvious.  The Mueller investigation into the real effort, attested to by every U.S. intelligence agency, of the Russians to rig an American presidential election is hurting Mr. Trump and the Republicans politically. It hurts so much precisely because it is being conducted by the Department of Justice under the direction of a Republican prosecutor of impeccable credentials.  Republican members of the Judiciary Committee desperately want to create a diversion, a means of planting in the public mind the impression that, whatever Trump did, Democrats did something as bad or worse.  It doesn’t matter if any real crime is uncovered, only that an investigation, with all the inevitable publicity, be commenced.  Of course, the House could investigate all these matters itself.   But the Republicans know that such investigations are easily dismissed as partisan.  Thus, only an investigation that bears the trusted stamp of the Justice Department will serve their political ends.

In short, the congressional Republican Party is consciously attempting to use the Justice Department’s hard-won, carefully guarded reputation for fairness and integrity to create a diversion from the real issues being investigated by Robert Mueller and the political damage that investigation is causing Mr. Trump and his allies.

Whether Jeff Sessions will crumple under the mutually reinforcing pressures from Mr. Trump, congressional Republicans, and his own self-interest remains to be seen.  If he does, the long-term damage to both American electoral democracy and the rule of law could be profound.

Several commentators, including Republican stalwarts like former Attorney General Michael Mukasey, have observed that launching criminal investigations of defeated presidential candidates is contrary to American norms and akin to the practices of “banana republics.”  This is profoundly true, but I suspect many do not fully appreciate the reference.

An indispensable feature of successful democracies is the peaceful transfer of power from one elected administration to its popularly chosen successor. Such transfers reliably occur only if the loser of an election knows that the sole consequence of losing is a return to private life. But if the predictable consequence of losing is criminal prosecution by the winner, then losing becomes unthinkable and the contestants are tempted to ever more extreme measures to prevent it.  Vicious propaganda, overt corruption, strong-arm tactics, ethnic incitement, all can be rationalized. All are soon normalized.  And democracy dies.  This is the all-too-common story in the developing world.  But regression is perfectly possible among mature democracies like our own.

Even if nothing quite so dramatic occurs and the Republican push for a Potemkin special prosecutor produces only a long, distracting, but ultimately unsuccessful investigation of Mr. Trump’s opponents, the damage to the Justice Department and thus to the rule of law would be lasting.  The best reading of the Department’s enigmatic Latin motto, Qui Pro Domina Justitia Sequitur, is that the Department’s lawyers are those “who prosecute on behalf of justice.” We trust the Justice Department with its immense powers because we trust it to wield those powers in pursuit of justice – to be honest, to be fair, to be apolitical.  And the Justice Department owes its effectiveness before courts and juries to our confidence in its probity.  If the public ever surrenders that confidence in favor of enduring suspicion that the Department is merely a tool of the party occupying the White House, then federal law enforcement will be irremediably crippled.  Every corrupt politician, slimy fraudster, and predatory corporation will scream “Politics!” at the first hint of a federal indictment.  Some will be believed.  And all of us will be less secure.

Not too long after the last election, I was on Capitol Hill talking with an aide to a Republican senator.  The probable appointment of Jeff Sessions as attorney general came up. When I wrinkled my nose a bit, my companion said, “At least with Jeff Sessions, you get a guy who knows the Justice Department and is committed to the rule of law.”

We will soon see if he was right.  Or whether Mr. Sessions will set in motion a train of events that could fracture an institution central to American democracy.

Frank Bowman