The American convention is certainly a sensible one

It would be ironic if the candidate who led the chant of “Lock her up” about his opponent ended up in jail himself. One of the worst features of modern politics is what might be called the criminalisation of disagreement: the idea that your opponents are so malign that they deserve not just to be defeated in debate or to lose an election but to go to jail.

So say all of us, including many people whose reflex when Tony Blair offers an acute opinion on coronavirus or Brexit is to say he should be in the Hague. Yet the case against Donald Trump might be different. He might go to jail not because a lot of people disagree with him but because he might have broken the law.

I am not referring, therefore, to his trial by the Senate, which is a mainly political procedure and which in any case is unlikely to succeed. It requires a two-thirds vote and therefore needs substantial support among Republican senators; even if it did succeed, the usual punishment would be to remove the president from office, which is irrelevant as the trial will be held after he has already left. Hence the talk of barring Trump from federal office, which is also irrelevant, as the only office in which he is interested is the Oval one and his chances of running for that in 2024 are now negligible.

If Trump does end up in jail it will be because the US courts will have put him there. The convention in the US is that former presidents are immune from prosecution, which is rather wonderful, because the country has a constitution that is supposed to do away with the muddled nonsense of the British way of doing things. As it happens, the American convention is a sensible one, precisely because it guards against the criminalisation of politics. It means that disagreements about a president’s policy while in office should not be relitigated in the courts afterwards.

That is partly why Gerald Ford pardoned Richard Nixon, and why the office of the independent counsel decided not to prosecute Bill Clinton after he left office. However, the point about a convention is that it is flexible. Paul Rosenzweig, a lawyer who advised the Clinton investigation, argued that “a reluctance to prosecute does not mean there should be a prohibition against doing so”, and that “it would be too great an affront to law for a president to have perpetual immunity”.

He quoted Theodore Roosevelt: “No man is above the law and no man is below it: nor do we ask any man’s permission when we ask him to obey it.” Thus Rosenzweig suggested that Trump should be prosecuted if there was evidence that he broke the criminal law as a private citizen, such as in his tangled financial dealings and allegations of sexual assault.  He argued that Trump’s actions as president should still be excluded, but he was writing before the storming of the Capitol, and the president’s role in inciting a rebellion against democracy.

If the case against Trump is strong enough for a court of law, this would be an extreme enough case to make another exception to the assumption of post-presidential immunity. No wonder Trump is reported to be considering pardoning himself, and other unconvincing devices to protect himself from prosecution. Many people watching Trump’s speech to the protesters on 6 January were convinced that he was inciting them to violence, despite his telling the crowd they “will soon be marching over to the Capitol building to peacefully and patriotically make your voices heard”. But it is striking that two former leader-writers for The Independent disagree about this.

David Aaronovitch, writing in The Times, said the president’s words amounted to: “Wouldn’t it be terrible if something happened to the lying, cheating, treacherous fraudsters who are sitting in that building over there that I’ve asked you to march to?” Whereas Mary Dejevsky wrote in our pages: “It is now taken as read that he ‘incited’ a mob, fomented an ‘insurrection’, conducted, as some say, a ‘self-coup’. I have scoured Trump’s utterances and can find no evidence for any of this.”