No president of the United States has ever been prosecuted. Richard Nixon, who likely came the closest, was rescued from the threat of criminal charges by a pardon bestowed by his successor, Gerald Ford. But now, in the wake of the Mueller report’s account of potential obstruction of justice by President Trump, Democratic politicians are beginning to weigh the possibility that Trump will be brought before a court.

“I want to see him in prison,” Speaker of the House Nancy Pelosi reportedly told House Democrats in a closed-door meeting earlier this month. And asked by NPR reporter Scott Detrow whether, as president, she would support bringing an obstruction case against Trump, Democratic presidential candidate Senator Kamala Harris answered: “I believe that [the Department of Justice] would have no choice and that they should, yes.”

Harris framed her answer in the language of justice: “Everyone should be held accountable, and the president is not above the law.” Yet her comments should be concerning to anyone who cares about maintaining the independence of law enforcement from political influence.