Can Congress investigate Trump’s commutation of Roger Stone’s sentence?

House Judiciary Committee Chairman Jerry Nadler, D-N.Y., last week vowed to investigate President Donald Trump’s decision to commute the prison sentence of his longtime associate Roger Stone.

“President Trump has infected our judicial system with partisanship and cronyism and attacked the rule of law,” Nadler said.

Trump on Friday commuted Stone’s sentence, sparing him from having to report to a federal prison in Georgia to begin serving 40 months behind bars. In November Stone was convicted of lying to Congress during the investigation into Russian election meddling.

But can Congress investigate a president’s grant of clemency?

As recently as last week, in its decision in the Trump congressional subpoena case, the Supreme Court said Congress’ power to investigate is tied to its power to make laws. It can demand information only if “it is related to, and in furtherance of, a legitimate task of the Congress,” and its investigations must serve a “valid legislative purpose.”

The court has ruled on this limitation of congressional power repeatedly, a conclusion it first expressed in 1927: that each House of Congress has the power “to secure needed information” in order to legislate. It made the same point in a different way in a 1957 case, ruling that “there is no congressional power to expose for the sake of exposure.”

Because the Constitution gives the president unlimited power to grant clemency for federal crimes, there’s no legislative hook allowing Congress to investigate.

This same issue came up in 2001 when Republicans in Congress wanted to investigate President Bill Clinton’s last-minute pardons. As former House general counsel Stan Brand said at the time, “It’s none of Congress’ business.”