The US has savoured an intoxicating sensation of late. Political normality. The violence at the capitol on January 6 has not recurred. Its agent, former president Donald Trump, has repaired to Florida. As for his successor, some of Joe Biden’s ventures (such as his fiscal relief plan) are wiser than others (such as his protectionism). But none are incendiary.

It is right to preserve this moment of national calm. Not, however, at any cost. On Tuesday, the Senate begins its trial of Trump, who was impeached for his role in the capitol siege by the House of Representatives. If it convicts, the large minority of the country that still swears by him will seethe. Any hopes of bipartisanship in Washington over the coming years will vanish. The US would relive the rancour from which it has just bought some relief.

And it would still be the right thing to do. “Incitement to insurrection”, the article of impeachment, is not too strong a phrase for what Trump attempted last month. With the connivance of other Republicans, he raised a mob against the certification of his election defeat. Five people died, including a police officer, and the lingering thought is how much worse it might have been.

To favour the quiet life over the application of the law is dangerous at any time. To do so when the charge is as grave as this one would compromise the state and its values. In the absence of new evidence to the contrary — the potential discovery of which is another good reason for a trial — the Senate must convict.

The test in the coming days is not just for the republic, but for the party that carries its name. Barring a miracle of conscience, not enough Republican senators will vote against Trump to clinch the required supermajority for conviction. This is a movement choosing unity over the hard and divisive work of purging its coarser elements. Even after January 6, a majority of its House members refused to certify Trump’s defeat. Spurious claims of voter fraud still abound.

Some Republicans behave like this out of sincere belief in the man and his cause. Others do so out of fear of a raging base. It is hard to know which impulse is worse, the zeal or the cowardice.

Either way, the Senate trial will force them on to the record, if not for voters, who have a pandemic and battered economy to distract them, then for posterity. After all, had the Senate convicted Trump on charges to do with Ukraine last year, the capital siege would never have happened. Historians will record that my-party-right-or-wrong is not a victimless dogma.

There are burdens on the Democrats, too. The party must focus the trial on the charge in question. This is not the setting for a tour of grievances spanning the whole Trump era. Given the other crises at hand, and the lack of documentation to sift through, the trial should also be as brisk as is consistent with a thorough treatment of the facts. Biden has shrewdly floated above the process so far, describing it as a Congressional matter. As far as he can, he should remain a unifying leader.

However painstaking they are, though, the Democrats have to be realistic. There is no way of holding Trump to account that does not disrupt the US’s hard-won calm. The country will have to steel itself for a period of turbulence ahead. It is preferable to moral and legal abdication. What happened last month was an attempted seizure of power by force. No democracy can tolerate such a crime or allow its orchestrator to hold public office again. It is important to know which senators disagree.