Garvan Walshe is a former National and International Security Policy Adviser to the British Conservative Party. He runs TRD Policy.

Three incidents this week show in how much danger the norms of constitutional democracy have been put.

Chemnitz, August 27, 2018. Around a stone head monument to Karl Marx, plonked in a square as if transplanted to the DDR from some Bolshevik Easter Island, gathered a few thousand extreme right Germans. They had been summoned there to protest the murder of a German, apparently by an Iraqi or Syrian, in a fight a few days before.

Fired up by their demonstrating, and giving Hitler salutes, they would go on a rampage, overhwelming the local police. The far-right Alternative Für Deutschland party made excuses for them. More extraordinary, while Chancellor Merkel was unequivocal in her condemnation, Horst Seehofer, Germany’s Interior minister, deployed the excuse-making “but”. “My deepest sympathies are with the loved ones of the knife attack victim,” he began, before adding the belated acknowledgement of law and order, “but I want to say clearly, that nothing justifies the call to violence or violent riots.”

“Militant democracy” — the watchword of the Federal Republic — this is not.

The New Statesman, August 28, 2018. Lord Jonathan Sacks, former Chief Rabbi of the UK and Ireland, denounced Jeremy Corbyn, leader of the Opposition, for giving a speech in which he said that ‘Zionists’ who had lived in England all their lives, didn’t understand irony. Sacks compared the comments by the leader of the Labour Party – the Labour Party, Neil Kinnock might repeat – to Enoch Powell’s “rivers of blood” speech.

Washington, DC, August 27, 2018. As flags around Washington were lowered to honour Senator John McCain, the stars and stripes on the White House flew shamelessly at full-mast.

What links these three events (five, if you include Marx himself and the original Nazis) is a contempt for the norms of liberal democracy, the rule of law, and civilised political competition. Behind them lurks an invidious distinction between designed to deny dignity to the human beings it places on the wrong side of the line.

For Marx it was class. For the Nazis their race hierarchy. For Corbyn it is imperialists versus the colonised. For PEGIDA and the new German far-right it’s Christian identity (though hardly Christian observance) versus Islam. For Trump, it’s personal.

Marx’s central idea was that the side you were on didn’t depend on your views, but your relationship to the means of production. His was social pseudoscience that classified people as sheep and goat. The old racism of the Nazis also used pseudoscience, this time of race. Their successors in Chemnitz do it by culture, arguing that Muslims can’t live in a democracy. Corbyn deprives “Zionists”, representatives of a colonising power, of political legitimacy (and not just Zionists: old-fashioned class hate has returned to the British Left with proposals to enumerate the social backgrounds of BBC journalists). The new far right mixes bad sociology predicting an inevitable clash of civilisations with dodgy neuroscience and absurd evolutionary biology (consider Jordan Peterson’s obsession with lobsters).

In each case, people are expelled from the political debate and denied legitimacy not on account of what they’ve said or done, but on account what group their enemies have assigned them to. (Trump’s innovation is narcissism: the category that matters is whether you’re for Trump or against him).

McCain, pugnacious maverick that he was, was no doubt delighted to be considered an enemy by Trump. He stood for two principles alien to the current occupant of 1600 Pennsylvania Avenue: human dignity and what Americans would call the Republic, but here in Britain used to be called the constitution.

For human dignity, when he opposed his own party’s use of torture and Trump’s attempt to reinstate it, and when he reconciled with the North Vietnamese solders who had tortured him. For the Republic, in his concession speech to Obama, his work in forging cross-party coalitions in the Senate, and on campaign finance reform. He understood that political debate should be fierce, but should be conducted against a background of norms – a political Geneva Convention, if you will – that limits the means used to conduct political battles.

Both were matters of honour to him. To McCain, the honourable soldier was one who distinguishes himself from a butcher by treating civilians and enemies with the respect they are due. Civilians, who ought not be harmed; or combatants, for whom violence is reciprocal. The honourable democratic politician does the same for her political opponents. The political contest should be intense (and a spurious consensus can leave serious problems to fester) but limited by a certain respect for one’s democratic opponents and their motives, and the voters who choose them as their representatives. The only end for which all means are justified is the preservation of the democratic system itself. Within that system mutual forbearance between people who believe in its legitimacy is a must.

The best way to honour John McCain is to practice politics by his principles. Though a Republican, he was the most militant of democrats.