The renewed interest of the FBI in Hillary Clinton’s emails points up one extremely unwelcome but inevitable fact about American politics for the next few years: whoever wins in a few days' time will find themselves constantly distracted by judicial proceedings, the threat of proceedings or various otherwise serious allegations. The tribulations and travails that did so much to damage the later presidential terms of Richard Nixon and Bill Clinton, particularly the threat of impeachment, may be there for Hillary Clinton even before she takes the oath of office. Donald Trump, meanwhile, has promised to sue the dozen or so women who have accused him of misconduct, once the campaign is over. More writs, in either direction, may follow.

Thus, the one thing that we do know is that whether it’s President Clinton or President Trump who succeeds Barack Obama, the legal or investigatory processes they will be involved in will consume their time, drain their emotional energy and prove an embarrassment to the nation. They would be a lame duck from day one.

That is not to say that the great machine of American governance will grind to a halt; but it is a reminder about just how unsatisfactory the choice facing the American people is. As with Watergate and the Monica Lewinsky affair, it shifts public debate away from other issues that matter to the US and the wider world far more. If the Congress is of a different political complexion to the incumbent in the White House, then vicious partisanship will only add to the frictions and the chaos.

None of this makes the respective allegations against Donald Trump and Hillary Clinton morally or legally equivalent. The real question for American voters, and an interested and concerned world, is how far it will distort the election. In other words, are these revelations sufficient to cancel out any consideration of where the candidates would take their nation? Are Mr Trump’s offensive remarks about Muslims or women sufficient to destroy his credibility, such as it is, on the economy and foreign policy? Are the mistakes Ms Clinton made while Secretary of State enough to disqualify her politically?

It is, though, Ms Clinton who is in the most difficulty with the law. Constitutionally, it is not clear what would happen if she were indicted, convicted or impeached before or during her time in office. Politically, though, the very threat of that would be sufficient to make her hold on power that much more precarious. It was that threat – not reality – of impeachment that pushed President Nixon out of office in 1974. Bill Clinton’s time in power was secured only after he was acquitted by the Senate after his actual impeachment after the Starr Report, in a saga that was shaming and, curiously, had echoes of The Donald, or the allegations surrounding him, about it. And who knows what kind of scandal might one day destabilise President Trump?