Donald Trump’s threat in Sunday night’s presidential debate to appoint a special prosecutor to go after Hillary Clinton’s use of a private email server is legally empty — but it’s genuinely dangerous. Federal regulations give the appointment power to the attorney general, not the president, precisely to protect us against a president who uses the special prosecutor as a political tool.
What separates functioning democracies from weak or failed ones is that political parties alternate in power without jailing the opponents they beat in elections. That sometimes means giving a pass to potentially criminal conduct, but that’s a worthwhile sacrifice for making republican government work.
The law itself has a telling history. After President Richard Nixon fired special prosecutor Archibald Cox in the Saturday Night Massacre, a Democratic Congress passed the Ethics in Government Act of 1978, which created an independent counsel who was appointed by a special judicial panel, not the president. The law was upheld by the U.S. Supreme Court in 1988 over the dissent of Justice Antonin Scalia — the only justice who said the executive was the only branch of government with the capacity of initiating a criminal investigation.
But the law expired in 1999. And it was never renewed in large part because of the perception that Kenneth Starr had gone too far as an independent prosecutor in going after President Bill Clinton.
After the independent counsel law lapsed, the Department of Justice adopted a formal regulation governing the appointment of special counsels that’s still in effect. The regulation says that the attorney general — not the president — has the legal authority to appoint a special prosecutor.
Several conditions apply. First, the attorney general must determine that a criminal investigation is warranted — a presidential directive isn’t enough. Second, an ordinary investigation must “present a conflict of interest” such that “it would be in the public interest” to appoint a special counsel.
The point of these restrictions is simple: to avoid a president using the special prosecutor’s office as a tool to go after political opponents.
That matters for a functioning democracy. As political scientists have long observed, democracy depends most basically on political alternation: When parties change places after an election, the winners allow the losers to stay in business, operate as an opposition and run for office again.
That alternation means winners don’t put their opponents in jail. If they do — or if the opponents fear that they will be jailed — then the incentive to accept defeat evaporates. Losers in that dire position instead will turn to wide-scale popular resistance or military coups. That’s only rational if the losers think they won’t be free to run for office again. Prosecuting opponents is the hallmark of democracy-ending dictatorship.
It may seem extreme to say that Trump’s promise to prosecute Clinton threatens alternation in the U.S. After all, American democracy is pretty stable. But other presidents have bent over backward to avoid such prosecutions — even to the point of condoning illegal behavior.
Gerald Ford’s pardon of Nixon is a prime example, even though the two were from the same party. Ford judged that the republic wouldn’t be well-served by prosecution of a former president. George W. Bush didn’t seek to prosecute Clinton for perjury, although legally he might have been able to do so.
And Barack Obama didn’t seek to prosecute Bush administration officials for acts that likely counted as torture.
In each instance, there were other political reasons to avoid prosecution. But the dominant rationale was surely that each president wanted to avoid the specter of using executive office to go after opponents or former presidents.
This shows that even in the U.S., the value of democratic alternation weighs very heavily — more heavily than criminal justice. Trump’s threat to jail Hillary Clinton shows he doesn’t value that tradition of alternation. Even if he’s not elected, that’s a dangerous view.
Noah Feldman is a Bloomberg View columnist.