The answer is an unequivocal yes, because these were criminal charges brought in federal court. The Constitution grants the president an effectively unbounded ability to pardon anyone before charges are proffered, during a trial, or after conviction, as well as to commute a sentence. It can be narrow or broad, and legal scholars suggest that the president could write a blanket pardon for a group of people.

He might even be able to issue a pardon in a tweet.

This ignores any political fallout from such pardons, which are unknown and unpredictable, given that the only recourse Congress has to oppose the president is to pursue impeachment, which, among other things, requires a majority of votes in the House to proceed to trial and a supermajority in the Senate to convict.

For the record, Trump has made a number of extraordinary and unprecedented pardons since taking office, but hasn’t done so for any of his associates facing jeopardy, charges, or sentencing.

The president’s power, however, extends only to federal charges. If a state attorney general or a county or other prosecutor were to bring charges and win a conviction—one affirmed in appeals, if any—Trump has no ability to pardon or commute.

So far, no such charges have been brought at other than a federal level.

The New York attorney general has at times been seen as somewhat of an ace in the hole if Trump pardoned associates convicted of federal crimes as many alleged activities took place in New York State or involved financial transactions in New York, and some state laws could apply. However, New York has a double-jeopardy statute that prevents someone tried on federal charges from being tried again on the same charges in state court. The previous state attorney general, who resigned after allegations of sexual abuse of partners, and the current one both have worked to have this statute overturned.

A pardon removes the penalty for a crime, and prevents a trial if one hasn’t occurred or shuts one down if it’s in progress. Someone convicted of a felony effectively is no longer a felon, even though the facts of the matter remain established.

Conservative political commentator and filmmaker Dinesh D’Souza pleaded guilty in 2014 to making illegal campaign contributions, and described his culpability in detail in the court proceeding. Trump pardoned him in May 2018, which wiped out the remainder of the probation he was required to undergo, and he regained his voting rights, among other benefits.

If someone has already been convicted, it effectively leaves the facts of the case as decided, and an appeal to have the conviction overturned is impossible. However, former Arizona sheriff Joe Arpaio, pardoned unexpectedly by President Trump in August 2017, continues to fight to have the original conviction on criminal contempt of court vacated.

Someone who has received a pardon no longer faces the burden of self-incrimination in court, and constitutional expert Laurence Tribe noted in July 2017 that a pardon recipient could be compelled to testify in court without a concern to themselves about facing charges as a result.

Trump has stated he can even pardon himself, but constitutional experts are mixed on that tactic. Any self-pardon would likely require a Supreme Court decision on the constitutionality, and there’s little sense that he would prevail. Even if he prevailed, impeachment isn’t subject to pardon (per Article II, Section 2 of the Constitution), and the president could have charges brought against him by the House, be convicted by the Senate, and be removed from office, even if there were no criminal charges against him.

There’s another twist. A 1974 memo from the White House Office of Legal Counsel laid out a scenario in which the president stepped aside from his duties temporarily invoking the 25th amendment, at which point the vice president would assume the presidency and could pardon the president. The president could then assert he was fit for duty, and return to the role.