With six months to go before President Bush leaves office, the White House is receiving a flurry of pardon applications. The New York Times reported that “several members of the conservative legal community” are pushing for the White House to grant pre-emptive pardons for officials involved in counterterrorism programs. Wait—can a president really pardon someone who hasn’t even been charged with a crime?

Yep. In 1866, the Supreme Court ruled in Ex parte Garland that the pardon power “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.” (In that case, a former Confederate senator successfully petitioned the court to uphold a pardon that prevented him from being disbarred.) Generally speaking, once an act has been committed, the president can issue a pardon at any time—regardless of whether charges have even been filed.

As the Explainer has pointed out before, there aren’t many limits to the president’s pardon power, at least when it comes to criminal prosecutions under federal law. The president’s clemency power has its origins in the practices of the English monarchy, and as a result, the Supreme Court has given the president wide leeway under Article II, Section 2 of the Constitution. There are some exceptions: The chief executive can’t pardon someone for a violation of state law or nullify a civil ruling, and his power doesn’t extend to convictions handed down in an impeachment proceeding. (It’s also not clear whether the president can pardon himself for future convictions.)

While pre-emptive pardons remain very rare, there are a few notable exceptions. Perhaps the most famous presidential pardon of all time occurred before any charges were filed. Gerald Ford’s pardon of Richard Nixon absolved the former president of “all offenses against the United States which he … has committed or may have committed or taken part in” between the date of his inauguration in 1969 and his resignation in August 1974. In other cases, presidents have pardoned individuals after criminal proceedings have begun but before a judgment has been handed down. In late 1992, less than a month before leaving office, President George H.W. Bush pardoned former Defense Secretary Caspar Weinberger, who had been indicted earlier that year on perjury charges surrounding the Iran-Contra affair. (A lawyer for Roger Clemens’ former trainer Brian McNamee claimed the pitcher might receive a similar pardon from Bush if he were ever indicted.) In addition, broad presidential amnesties—like the one President Carter issued to those who had avoided the draft during the Vietnam War—are essentially pre-emptive pardons issued to a large group of individuals.

If someone hasn’t yet been charged with a crime, how does the president know what to pardon them for? As in Nixon’s case, President Bush could issue a pardon that applies generally to any crimes that may have been committed within a certain range of dates. More likely, a pardon could apply only to actions surrounding a single policy or place—say, the detention or interrogation of suspected al-Qaida members.

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Explainer thanks Ken Gormley of Duquesne Law School, Harold Krent of the Chicago-Kent School of Law, and P.S. Ruckman Jr. of Rock Valley College and PardonPower.com. Thanks also to reader Marcus Beck for asking the question.