On Tuesday, a jury in Virginia convicted former Trump campaign chair Paul Manafort on eight federal felony charges, including five tax fraud charges, two bank fraud charges, and one charge of hiding foreign bank accounts, related to his work for pro-Russian politicians in Ukraine. The combined charges carry a sentence of up to 80 years, with more to come if special counsel Robert Mueller tries Manafort again on the 10 counts on which the jury deadlocked.

Manafort will likely appeal the verdict, but the case might not even get that far. Even before Manafort’s initial indictment, observers have speculated that President Donald Trump might pardon Manafort.

Indeed, the idea of a pardon helps makes sense of Manafort’s decision not to cooperate with investigators, even though cooperation could save him years or decades of prison time.

It wouldn’t be Trump’s first contentious pardon; previously he gave ones to conservative conspiracy theorist Dinesh D’Souza and former Bush administration official Scooter Libby. But pardoning Manafort would be especially controversial given Manafort’s place at the center of investigations into what Trump did or did not know about Russian intelligence’s efforts to influence the 2016 election, and whether Trump himself was involved in those efforts. Pardoning Manafort would look like, and perhaps be, an effort to use presidential power to cover up Trump’s own wrongdoing.

Those optics mean it might make political sense for Trump to hold off on pardons, as Vox’s Andrew Prokop explains here. What’s more, as multiple law professors told my colleague Sean Illing, pardoning Manafort might deprive him of his Fifth Amendment right not to testify when subpoenaed, potentially putting Trump in more legal jeopardy.

But whether or not pardoning Manafort is a good idea for Trump personally, Trump certainly can do it. The presidential pardon power is basically unlimited. It can be used to obstruct justice, yes, and in that case, Congress would have the power to impeach and/or remove Trump if it so chooses. But it cannot undo Trump’s pardons, or limit them in any way, once they’ve been granted.

So Trump could pardon aides like Manafort after they’re convicted, as a reward for loyalty, or he could pardon others before their trial. He could even deliver a blanket pardon for Jared Kushner, Donald Trump Jr., and any other people he worries could be charged in the future but have not been yet.

This is not just hypothetical. Former Trump lawyer John Dowd reportedly floated the option of pardons to attorneys for both Manafort and former National Security Adviser Michael Flynn last year. (Such a deal appears not to have occurred with Flynn, who cut a deal with prosecutors in December.)

“He can definitely pardon people who haven’t been charged yet,” Brian Kalt, a law professor at Michigan State University and author of Constitutional Cliffhangers: A Legal Guide for Presidents and Their Enemies, told me last July. “And, contrary to a common misconception, it doesn’t require as a legal matter that he say they are guilty.”

By eliminating whatever advantage his staffers and family members would gain through cooperation with special counsel Mueller, Trump would protect himself and other aides against incrimination. But he would also deny the people he pardons the ability to invoke the Fifth Amendment, which allows possible future defendants to decline to answer questions under oath that they feel might incriminate them. Because they would be immune from prosecution, they by definition couldn’t incriminate themselves and thus couldn’t plead the Fifth. They would have to testify if subpoenaed.

That said, they could always lie, and if proven to be lying and charged with perjury — well, Trump could just pardon them again. It would be a grotesque abuse of power, but it would be completely legal.

There is one important limit to Trump’s powers, however. The New York state attorney general and Manhattan district attorney are also investigating Manafort, with cooperation from Mueller’s team. And, tellingly, Mueller declined to indict Manafort for a number of offenses that are also crimes in New York, suggesting he wants to make such prosecutions possible.

Should Manafort or any other Trump loyalists face state-level charges, they could not be pardoned by President Trump, offering one possible avenue through which prosecutors can target aides without running afoul of the pardon power.

Presidential pardoning powers are vast

The Supreme Court actually ruled on the pardon power in the 1866 case of Ex parte Garland. That decision concerned a law Congress passed disbarring former members of the Confederate government, which was challenged by former Confederate Sen. Augustus Hill Garland.

President Andrew Johnson had pardoned Garland, and Garland argued that this shielded him from disbarment under the law. The Supreme Court agreed, and in doing so clarified that the pardon power is basically unlimited and can be applied to any crime, whether the pardoned person has been charged or not.

“By the second section of the second article of the Constitution, power is given to the President ‘to grant reprieves and pardons for offences against the United States, except in cases of impeachment,’” Justice Stephen Field wrote. “With that exception the power is unlimited. It extends to every offence, and is intended to relieve the party who may have committed it or who may be charged with its commission, from all the punishments of every description that the law, at the time of the pardon, imposes.”

Presidents have since taken advantage of this latitude. Ford’s pardon of Nixon occurred before Nixon could be charged with anything, so he gave Nixon a sweeping pardon covering every federal offense during his presidency:

Now, Therefore, I, Gerald R. Ford, President of the United States, pursuant to the pardon power conferred upon me by Article II, Section 2, of the Constitution, have granted and by these presents do grant a full, free, and absolute pardon unto Richard Nixon for all offenses against the United States which he, Richard Nixon, has committed or may have committed or taken part in during the period from January 20, 1969 through August 9, 1974.

Trump could, similarly, offer any number of his aides “a full, free, and absolute pardon … for all offenses against the United States … [they] committed or may have committed or taken part in during the period from January 1, 2016 through July 21, 2017,” or earlier or later, as he sees fit.

This might cause problems for Trump himself, however. Just as selling pardons would run afoul of the bribery statute, University of Chicago’s Daniel Hemel and Eric Posner argue that using the pardon power to obstruct the Russia investigation could constitute obstruction of justice. “In Trump’s case, the question would be whether he was acting out of the goodness of his heart, or covering up for his family, his associates and himself,” Hemel and Posner write.

Eleven legal experts contacted by Vox’s Sean Illing agreed. “While the pardon power is quite broad under the Constitution, that does not mean that exercises of the pardon power — or promises to grant pardons — cannot be obstructive,” Lisa Kern Griffin of Duke said. “Like any other lawful act, such as terminating executive branch employees, a pardon could be unlawful if done with the corrupt intent to impede an investigation or influence a witness.”

That being said, because most observers believe the president cannot be indicted while in office (and certainly not by federal prosecutors for obstructing a federal investigation), the question of whether the pardons constitute obstruction of justice mostly matters inasmuch as it changes House and Senate leadership’s attitudes toward impeachment.

If it is indeed obstruction but House Speaker Paul Ryan and most Republicans disagree, it’s doubtful Trump will face any concrete consequences as a result.

Many states control pardons. The federal government doesn’t.

While there’s no federal precedent for Trump pardoning his aides, there is one at the state level. Some state governors have pardon powers mirroring that of the president, and in 2005, Kentucky Gov. Ernie Fletcher (R) offered blanket pardons to current and former aides in his administration who did or could face charges from a grand jury investigating the administration’s violations of merit-based hiring laws. Later, a Kentucky Supreme Court ruling affirmed that the grand jury could not indict anyone to whom Fletcher’s pardon applied.

Eventually, Fletcher himself was indicted on three misdemeanor charges. He quickly lost popularity due to the scandal and lost his 2007 bid for reelection by a wide margin.

Kentucky is an unusual state in that it imposes relatively few limitations on the pardon power. Several states, including Connecticut, Georgia, South Carolina, and Utah, have independent boards that offer pardons in most cases, in place of the governor. In Minnesota, the governor and other top officials sit as a board and determine pardons.

“A number including Pennsylvania and Delaware, and Texas, have gatekeeper boards that put limits on what the governor can do,” Margaret Love, who served as US pardon attorney from 1990 to 1997, explains. “You can’t do anything without an affirmative recommendation from the board.” All told, she estimates that only 15 to 16 states have pardon powers as unrestricted as that at the federal level.

Changing the federal pardon power would require a constitutional amendment. But given the potential for abuse illustrated in the Fletcher case and by Trump’s situation, an amendment might be in order.

Can Trump pardon himself?

While Trump could pardon Manafort, Michael Cohen, Donald Trump Jr., Jared Kushner, and really anyone he wants, what’s less clear is whether he can pardon himself.

Presidents definitely can’t use the pardon power to impede impeachment proceedings against themselves or any other officials. But there’s disagreement among legal experts about whether the president can use a pardon to defend himself against future prosecution upon leaving office.

The Justice Department’s Office of Legal Counsel ruled in 1974 that Nixon could not pardon himself, but most legal experts consulted by Vox’s Illing concluded the opposite, that Trump probably could pardon himself. There’s also a question of whether courts would be willing to step in and disrupt a self-pardon, even if it’s not constitutionally permissible.

“It’s a ‘how many troops has the pope’ sort of thing,” Love told me in July.

Correction: This article originally stated that Manafort faces 240 years in jail; he faces a maximum of 80 years.