As the special counsel investigation into Russian interference in the 2016 election continues to close in on President Donald Trump and his closest advisors, there have been reinvigorated concerns that he will attempt to use his pardon power to undermine the investigation.

While concerns about the lengths to which Trump will go to protect himself and his inner circle from accountability are well-founded, there are important limits to the pardon power. The president’s pardon power cannot be used to: (1) pardon state crimes, (2) remove federal civil liability, (3) pardon impeachment, or (4) pardon crimes that have not already occurred.

The first three limitations and their application to Special Counsel Robert Mueller’s investigation have been thoroughly explored, including in a detailed report by Noah Bookbinder, Norman Eisen, Caroline Frederickson, and Conor Shaw. But the fourth limitation has not received similar attention.

This fourth limitation is important because it constrains Trump’s ability to protect co-conspirators from federal criminal liability for a conspiracy that involves the use of the pardon power. A conspiracy to obstruct the investigation that includes the use of the pardon power could not be subsequently pardoned by Trump; a pardon can only apply to actions that occur before it is issued, but in this case any obstructive pardon would be a continuation of the conspiracy, so the crime would be ongoing. Put another way: you cannot pardon a crime when the pardon itself continues the crime.

Pardons only apply to past acts

The president’s pardon power is exceedingly broad, but it only applies to actions that have already occurred, not those that are ongoing. As the Supreme Court noted in Ex parte Garland:

The Constitution provides that the President “shall have power to grant reprieves and pardons for offences against the United States, except in cases of impeachment.”

The power thus conferred is unlimited, with the exception stated. It extends to every offence known to the law, and may be exercised at any time after its commission, either before legal proceedings are taken or during their pendency or after conviction and judgment. (Emphasis added).

While the Court recognizes that the pardon power is broad, it explicitly states that pardons only apply to an offense “after its commission.”

A similar understanding is reflected in United States v. Wilson, in which the Court notes that: “A pardon is an act of grace, proceeding from the power intrusted [sic] with the execution of the laws, which exempts the individual, on whom it is bestowed, from the punishment the law inflicts for a crime he has committed.” (Emphasis added).

As pardon expert Brian Kalt has observed: “the law is clear that a pardon cannot be prospective… It is implicit in the definition of a ‘pardon’ as opposed to a suspension of the law.” To allow pardons for ongoing or future crimes would mean the president could suspend any and all laws for any person or group of persons, making a mockery of our legal system.

This limitation of the pardon power has been reflected in presidential practice. While people have been pardoned for conduct for which they have not been charged, as in the case of Richard Nixon, no president has ever attempted to pardon an individual or individuals for actions that are ongoing or yet to occur.

Note, however, that in his pardon of Joe Arpaio for criminal contempt stemming from his violation of people’s constitutional rights, Trump included ambiguous language that could be read as an illegal attempt to pardon future conduct. Trump pardoned Arpaio for his criminal contempt charge and “for any other offenses…that might arise, or be charged, in connection with Melendres v. Arpaio.” (Emphasis added).

Mueller is investigating a broad conspiracy to influence the 2016 election

Collusion is a shorthand term that encompasses a range of potential criminal violations arising from coordination between the Trump campaign and Russians seeking to unlawfully intervene in the 2016 election. Perhaps chief among them is the crime of conspiracy (18 U.S.C. § 371), either to commit an offense against the United States or to defraud the United States.

A conspiracy is an ongoing crime:

Since conspiracy is a continuing offense, United States v. Kissel, 218 U. S. 601, 610 (1910), a defendant who has joined a conspiracy continues to violate the law “through every moment of [the conspiracy’s] existence,” Hyde v. United States, 225 U. S. 347, 369 (1912), and he becomes responsible for the acts of his co-conspirators in pursuit of their common plot, Pinkerton v. United States, 328 U. S. 640, 646 (1946).

The 2018 U.S. Attorney’s Manual makes a similar point: “the conspiracy is deemed to continue until its purpose has been achieved or abandoned. See United States v. Northern Imp. Co., 814 F.2d 540 (8th Cir. 1987); United States v. Coia, 719 F.2d 1120 (11th Cir. 1983), cert. denied, 466 U.S. 973 (1984).”

Conspiracy was among the charges brought against 12 Russians for the hacking and release of emails during the 2016 presidential election, as well as the 13 Russians and 3 companies who ran a social media campaign intended to help the Trump campaign. To the extent that Americans assisted, or continue to assist, Russia in these or other efforts to evade U.S. law, they are co-conspirators and could be charged as such.

When the pardon is part of the conspiracy

Because conspiracy is an ongoing crime, an obstructive pardon for actions related to a conspiracy involving the president would not eliminate legal liability. Either the pardon would be a continuation of the crime, and thus the pardon itself would be an invalid attempt to pardon actions that were ongoing, or the pardon would be a new conspiracy and thus a new crime—in either case, Trump and his accomplice or accomplices would still be subject to legal liability for conspiracy.

This is more than just a theoretical matter. Some legal experts believe that former Trump Campaign Chair Paul Manafort’s bizarre behavior, including lying to federal investigators and continuing to provide information to the Trump legal team, are best explained as an effort to secure a pardon in exchange of helping Trump. Moreover, there have been reports that Trump’s lawyer discussed possible pardons with Manafort and former National Security Advisor Michael Flynn.

A conspiracy charge for an obstructive pardon would not be novel. In U.S. v. Mitchell, the Watergate indictment, individuals were charged with conspiracy to defraud the United States, obstruct justice, make false statements to federal law enforcement, and commit perjury. (President Nixon was famously an unindicted co-conspirator). One of the alleged means by which they carried out the conspiracy was that “the conspirators would make and cause to be made offers of leniency, executive clemency and other benefits to [the Watergate burglars].”

This is not the only legal liability Trump and any associate would face if he used the pardon power to obstruct an investigation. They could be opening themselves up to charges of bribery and obstruction of justice. Such charges would not be without precedent: the Department of Justice investigated. President Bill Clinton to see if his pardon of Marc Rich constituted bribery, obstruction of justice, or any other illegal act. Independent Counsel Lawrence Walsh also considered whether President George H.W. Bush “exercised his constitutional prerogative to pardon a former close associate to prevent further Iran/contra revelations,” but declined to bring it before a grand jury because of “the absence of evidence that the pardon was secured by corruption.”

In addition to criminal charges, there could political ramifications as well, given that obstructing justice through pardons is an impeachable offense.

But, unlike with these other charges, the ongoing nature of a conspiracy charge could ultimately prevent Trump from being able to protect his associates. If the pardon furthered the conspiracy, it would be invalid because it sought to pardon ongoing activity, which is outside the scope of the pardon power. It would be like trying to pardon someone for theft in the middle of a bank robbery. To the extent the pardon was the start of a new conspiracy, it would create legal liability rather than eliminating it. There would be no concerns with respect to double jeopardy either, since the pardon would be either invalid or a wholly new crime.

Taken a step further, the special counsel might argue that, to the extent the pardon recipient was a part of the larger conspiracy to interfere in the 2016 election, this subsequent act was a continuation of that conspiracy. After all, the use of the pardon power in this manner would interfere with lawful government functions by preventing enforcement of the law with respect to the election interference that is the subject of the larger conspiracy.

All of this should give Trump associates and would-be co-conspirators real pause. Not only are presidential pardons unable to protect against state criminal charges and federal civil suits, but they also cannot protect against federal criminal liability if they are in furtherance of a conspiracy to obstruct justice. Not welcome news for those desperately seeks to avoid accountability for their actions.

Trump associates who have shunned or are considering shunning plea deals in the hopes of securing a presidential pardon would do well to consider a twist on an old maxim: it’s not the crime, it’s the cover-up that continues that crime.

Image: Paul Manafort arrives for a court hearing on June 15, 2018 in Washington, DC. Photo by Brendan Smialowski/AFP/Getty Images.