Yes, Trump could be indicted. The ‘Nixon tapes’ case proves it.

As special counsel Robert S. Mueller III racks up indictments and guilty pleas, and President Trump continues to dig himself further into a potential obstruction-of-justice charge, a question lingering since Mueller’s appointment comes front and center: May a sitting president be indicted for a federal crime?

I believe the answer is yes. When I was counsel to the Watergate special prosecutors, one of the issues that we had to address during the investigation of President Richard Nixon was whether the president was subject to indictment for his role in the Watergate coverup. As we later informed the Supreme Court in briefing the “Nixon tapes” case, we concluded that a president may be indicted while still in office. The Justice Department’s Office of Legal Counsel has taken a different position, first under Nixon and later under the administration of President Bill Clinton.

In fact, in the Nixon tapes case, the Supreme Court rejected essentially the same point that Trump supporters are making. There Nixon argued that, as chief executive overseeing enforcement of the federal laws, he was not subject to demands by the special prosecutor that the president produce evidence sought by the prosecutor. The court unanimously upheld the fundamental constitutional principle that no person is above the law, and even the president is subject to the ordinary obligations and prohibitions of federal law applicable to everyone else. The caption of the case says it all: United States v. Richard M. Nixon, President of the United States.

Whether Mueller and a grand jury conclude that Trump has violated the federal criminal law against obstruction of justice is a complex matter. There may be reasons of “prosecutorial discretion” not to pursue a criminal charge, even if one is otherwise justified. But the president and his supporters are claiming an immunity from criminal culpability that our constitutional system of justice does not and should not tolerate.