Former President Donald J. Trump says he is prepared to prosecute his political enemies if he is elected this fall. Simply making those threats, legal experts said, does real damage to the rule of law.
But if he is already challenging bedrock norms about the justice system as a candidate, Mr. Trump, if he wins the presidency again, would gain immense authority to actually carry out the kinds of legal retribution he has been promoting.
The Justice Department is part of the executive branch, and he will be its boss. He will be able to tell its officials to investigate and prosecute his rivals, and Mr. Trump, who has made no secret of his desire to purge the federal bureaucracy of those found insufficiently loyal to his agenda, will be able to fire those who refuse.
While the department has traditionally had substantial independence, that is only because presidents have granted it. If the legal system resists political prosecutions in a second Trump term, it will be largely because judges and jurors reject them.
Mr. Trump’s musings on his planned prosecutions serve an immediate political purpose, highlighting his argument that his conviction in New York was the product of an effort by Democrats to keep him from being elected again and providing the red meat of prospective retribution to his base.
But they also have the effect, partly incidental and partly calculated, of undermining faith in the integrity of the criminal justice system, a development that could have profound effects in a nation where the rule of law has been foundational.
Mr. Trump and his supporters have argued that the system is already politicized, pointing to the four criminal prosecutions against him as irrefutable evidence — an assertion rejected by those who say that no one, including a former president or leading presidential candidate, is above the law.
In effect, Mr. Trump’s candidacy is becoming a referendum on what kind of justice system the country believes it has now and wants to have in the future.
“Trump ordering the prosecution of his opponents would be an epic abuse of power,” said Michael Waldman, the president of the Brennan Center for Justice. “It would revert to a time before Watergate, when presidents used the F.B.I. and I.R.S. to go after perceived enemies and even just partisan opponents.”
Attitudes have changed since then, and they could change again.
“As a constitutional matter, the president has law enforcement discretion to prosecute anybody,” said David B. Rivkin Jr., who served as a lawyer in the administrations of President Ronald Reagan and President George H.W. Bush. “You don’t get immunized because you are the enemy of a president.”
Mr. Trump has long mused about sending Hillary Clinton to prison, and he returned to that theme on Tuesday in an interview with Newsmax.
“Wouldn’t it be terrible to throw the president’s wife and the former secretary of state, think of it, the former secretary of state, but the president’s wife, into jail?” he asked. “Wouldn’t that be a terrible thing? But they want to do it. It’s a terrible, terrible path that they’re leading us to. And it’s very possible that it’s going to have to happen to them.”
The president can certainly instruct his attorney general to investigate given individuals. In his 1960 presidential campaign, for instance, John F. Kennedy pledged to target Jimmy Hoffa, the labor leader. “In my judgment, an effective attorney general with the present laws that we now have on the books can remove Mr. Hoffa from office,” Kennedy said.
Days later, he added that he was frustrated “when I see men like Jimmy Hoffa — in charge of the largest union in the United States — still free.” (Hoffa was eventually convicted of jury tampering and fraud.)
The federal criminal code was a relatively modest document when Kennedy spoke. These days, it is a vast compendium. In “Three Felonies a Day: How the Feds Target the Innocent,” Harvey A. Silverglate argued that the average American professional unwittingly commits several serious crimes each day.
Neil S. Siegel, a law professor at Duke, said the norm against political prosecutions is “essential to sustaining the rule of law, which is the antithesis of the rule of powerful individuals who weaponize the coercive power of federal criminal law.”
While presidents can order investigations, and while much conduct can be characterized as criminal, there are circuit breakers in the legal system, said Mr. Waldman, the author of “The Supermajority: How the Supreme Court Divided America.”
“For Donald Trump to be able to abuse power this way would require prosecutors to cooperate, would require the F.B.I. and others to shed their independence, and for grand juries and judges to go along,” he said.
But all of that is but a small comfort, he said.
“We should not have to rely on the backbones and professionalism of those individuals,” Mr. Waldman said. “In the modern era, if a president orders a prosecution we would be uncharted territory.”
Mr. Rivkin, an author of a recent opinion essay in The Wall Street Journal arguing that Mr. Trump’s felony convictions in New York violated his right to due process, said the former president’s threats were “mostly bluster.” But he added that they were problematic.
“It is certainly the case that law enforcement should not be wielded with political considerations in mind,” Mr. Rivkin said. “In particular, it’s one of those instances where talking about it makes it worse.”
Ilya Somin, a law professor at George Mason University, said the problem had grown more acute given Mr. Trump’s efforts to draw lessons from his first stint in the White House.
“This would be a bigger menace in his second term than it might have been in his first,” Professor Somin said. “In the first term, there were a lot of people working for him who were not willing to act on his worst impulses. The second administration would be staffed by people more willing to do his bidding.”
Mr. Trump’s allies say the hypothetical prosecutions he might pursue pale in comparison to the four actual ones against the former president, three of them stalled and one that yielded a conviction on 34 felony counts. Professor Siegel, the author of a 2018 article in The Indiana Law Journal called “Political Norms, Constitutional Conventions and President Donald Trump,” said the two were different.
“Trump is not being prosecuted just because he is someone’s political enemy,” Professor Siegel said. “He is being prosecuted in multiple federal and state courts in unprecedented fashion because his misconduct in office and as a candidate was sufficiently egregious that it threatened the basic stability of American democracy and the rule of law in this county, not to mention the existence and relevance of truth as a category of political life.”
In April, when the Supreme Court heard arguments over Mr. Trump’s claim that he is absolutely immune from prosecution on charges that he used his office to subvert the 2020 election, Justice Samuel A. Alito Jr. said prosecutions of former presidents are problematic.
“If an incumbent who loses a very close, hotly contested election knows that a real possibility after leaving office is not that the president is going to be able to go off into a peaceful retirement but that the president may be criminally prosecuted by a bitter political opponent, will that not lead us into a cycle that destabilizes the functioning of our country as a democracy?” he asked. “And we can look around the world and find countries where we have seen this process, where the loser gets thrown in jail.”
The question, said Robert Gordon, a law professor at Stanford, is “a bit more difficult than it looks.”
“A party may come into power determined to address injustices committed by the prior regime, as Argentina criminally charged leading generals after the dirty war, or Brazil is doing now against its former president,” he said. “But the claims of injustices have to be true and their investigation and prosecution scrupulously fair.”
“It’s pretty obvious,” Professor Gordon said, “that turning law enforcement against your political opponents just to get revenge on them is among the worst crimes a regime can commit.”
