At a pivotal moment during one of the Watergate hearings in 1973, President Richard Nixon’s counsel, John Dean, asked a question that still resonates: “How in God’s name could so many lawyers get involved in something like this?”

In the aftermath of Nixon’s resignation, the issue posed by Mr. Dean’s bracing question triggered a revolution in the legal profession. With so many lawyers involved in the Watergate criminal scheme, the American Bar Association started requiring law schools to provide ethics instruction or risk losing their accreditation. Exams began testing law students’ knowledge of intricate ethical rules.

It wasn’t enough, if the past few weeks are any guide. In Fulton County, Ga., three of former President Donald Trump’s lawyers — Kenneth Chesebro, Sidney Powell and Jenna Ellis — have now pleaded guilty to crimes in service of Mr. Trump’s scheme to overturn the 2020 election and stay in the White House. All three have agreed to cooperate with prosecutors in the sprawling state RICO case against Mr. Trump. Two other Trump lawyers, Rudy Giuliani and John Eastman, still face criminal charges in the Georgia case. They, along with Mr. Chesebro and Ms. Powell, have also been identified as unindicted co-conspirators in the related federal prosecution of Mr. Trump, which will probably benefit from the guilty pleas in Georgia.

The charges in the plea agreements vary, but the underlying story is the same: Fifty years after Watergate, the nation is once again confronted with a president who grossly abused the powers of his office, leading to criminal prosecutions. And once again, that abuse relied heavily on the involvement of lawyers. If Mr. Trump’s 2020 racket was “a coup in search of a legal theory,” as one federal judge put it, these lawyers provided the theory, and the phony facts to back it up. In doing so, they severely tarnished their profession.

How in God’s name? The question is no less urgent now than in 1973. Lawyers hold immense power within the American system of government, which depends on their expertise, and their integrity, to function. Those who abuse this power pose an even greater threat to the country than some random Capitol rioter, because we count on them not only to draft and execute the laws but to follow them — to lead by example. Everyone should behave ethically, of course, but despite the “Better-Call-Saul” reputation of so many lawyers, there’s nothing wrong with holding the profession to a higher standard.

One can view the guilty pleas by the Trump lawyers as evidence that the system is working as it should. They broke the law, they violated their ethical obligations, and now they are facing the music — not only in the courts, but from their chosen profession. Mr. Giuliani’s New York law license was suspended for his “demonstrably false and misleading statements” on Mr. Trump’s behalf; the District of Columbia’s bar association has recommended he lose his license there for good. Ms. Ellis was censured by Colorado state bar officials for violating the rule against “reckless, knowing, or intentional misrepresentations by attorneys,” and may face more severe consequences in light of her guilty plea.

Mr. Eastman, a former law-school dean and one of the key legal architects of Mr. Trump’s bonkers plot to stay in office, is in the final days of his California disbarment trial for ethical violations. Officials there have argued that his conduct was “fundamentally dishonest and intended to obstruct the lawful certification” of President Biden’s victory.

All of this is to the good. Careers are rightly ruined over such behavior. It is also the exception to the rule. In the real world, lawyers rarely face any consequences for their legal or ethical transgressions.

“It’s a club,” said Stephen Gillers, a legal-ethics expert at New York University School of Law who has studied the profession’s opaque and feckless disciplinary system. “The judges who make the decisions are lawyers in robes. They tend to be sympathetic to the other lawyer.”

And it’s hard to gloss over the fact that a disturbing number of experienced attorneys, some of who once held prestigious posts in government and academia, were willing and eager to tell transparent lies and concoct laughable legal arguments to help a con man stay in the White House against the will of the American people.

“Part of the reason Trump had to resort to attorneys to attempt the overthrow of the election was because the military was not available to him,” Norm Eisen, a senior fellow at the Brookings Institution, told me. Recalling the notorious Dec. 18, 2020, Oval Office meeting, during which the former president openly contemplated ordering the armed forces to seize voting machines, Mr. Eisen said, “It’s a testament to our military leaders, to our military culture, that that door was closed.”

The same cannot be said, alas, for America’s legal culture. It’s easy enough to understand why Mr. Trump, who was mentored by the ruthless mob lawyer Roy Cohn, would seek out lawyers who were willing to do whatever he asked, legality and ethics be damned. The more troubling question is how he was able to find so many takers.

The obvious answer is the eternal seduction of money and power. Laurence Tribe, one of the nation’s foremost constitutional scholars, fell back on that explanation for the choices made by Mr. Chesebro, his former student, referring to him as a “moral chameleon” who was engaged in deeply dishonest lawyering.

Related to this is the intense pressure to satisfy the demands of powerful clients, even if it means bringing lawsuits so frivolous that they can result in legal sanctions, as many of Mr. Trump’s lawyers have learned the hard way.

There is an important caveat here: Many government and private lawyers in 2020, faced with Mr. Trump’s illegal and unconstitutional demands, resisted the temptation and behaved honorably. From the White House counsel’s office to the Justice Department to top law firms, some key attorneys held the line.

“What was one of the determinative factors in Trump’s coup failing?” asked Ian Bassin, executive director of the advocacy group Protect Democracy. “Responsible lawyers refused to participate.”

That explains why many of the lawyers caught up in Mr. Trump’s outrageous plot were not what you might call the cream of the crop. They were grifters, shysters, hair-dye-leakers, tapped primarily because Mr. Trump had trouble finding more serious people to make his case. And yet there were still those with more respectable backgrounds, like Mr. Chesebro, who chose to sell their honor to a man devoid of it, and who they should have known wasn’t going to pay them anyway. In the end, they were all smeared with the humiliation of having filed meritless, fact-free cases. With one minor exception, federal and state courts rejected every lawsuit brought on behalf of Mr. Trump.

To a degree many people didn’t fully realize until the past few years, the functioning of American government depends on honor. “There are no guarantees in a democracy,” Mr. Eisen said. “Our rule of law is a central part of what defines our democratic system. Ultimately it comes down to whether the majority of people will do the right thing.”

When it comes to lawyers, the choices of just a few can make all the difference.