Two weeks ago, some readers may recall, I mentioned a report on surveillance, commissioned by the Information Commissioner's Office. The issue then was the use of a statistic about CCTV that turned out to be fictitious. But this “fact” wasn't the only debatable citation in the report.

In another paragraph the authors were attempting to persuade their audience of the dangers of governments holding information. As evidence for their contention that “efficient national databases can be used for the provision of targeted health care or for the victimisation of political opponents”, this example was given: “Historically, IBM's punch-card machines were essential to the efficient operation of the massive system of population surveillance that enabled the Nazis to single out Jews and other ‘undesirables' for imprisonment and extermination.”

I had read a lot of stuff on the Holocaust, from its foetal stage as prejudice, through its infancy of boycotts, racial laws and broken windows, to its full awful adulthood. But I had never once encountered the assertion that Nazi databases had played any very large role in the delivery of the extermination of the Jews (thinking about it, the rail system might have been regarded as a likelier technological candidate).

This doesn't feel surprising: most of the Jews killed in the Shoah were from Eastern Europe, rounded up in Poland, Slovakia or Hungary and sent to ghettos and then to death camps, or taken from their homes in Russia and shot in mass executions, like the one at Babi Yar near Kiev. What “singled out” Jews was not their existence on a German database but their existence in Jewish communities, their possession of a Jewish name and, often, their appearance.

It took me nearly no time to discover that there is really only one source for this contention - a highly controversial book on IBM and the Holocaust by an American journalist called Edwin Black. Sure enough, Black's book does appear in the report's appendix, though the contested nature of his argument isn't mentioned at all. But let that go, because my point is not about sloppy scholarship - it's about politics.

So last Wednesday morning I went out and about counting CCTV cameras with another journalist - much younger than me. We agreed that (a) there were lots of cameras and (b) we didn't know what many of them were there for, and didn't have time to ask.

But it was our discussion, en route, that interested me more. I had said to him - under the camera in the Costa coffee bar in the Trafalgar Square Waterstone's, I think - that this concentration on technology was in danger of missing the point. If, by some mischance, we had an authoritarian regime come to power, then that government would do bad things, whatever the law and however many cameras there were. He replied that he would rather live under an authoritarian regime that didn't have access to good databases than one that did.

He was worried by the gadgets, but to me the politics was almost everything. I didn't start the Third Reich analogy, nevertheless I'll stick with it. Hitler came to power legally in 1933, leader of the largest party in Germany. At the end of February, after the Reichstag fire, he rushed through his Emergency Decree for the Protection of People and State which suspended freedom of speech and assembly. A month later the Reichstag passed the Law for the Alleviation of the People's and the Reich's Misery, or Enabling Act, which allowed Hitler to rule without parliament. The necessary two thirds majority for this granting of dictatorship was gained with the help of intimidation and gerrymandering, and had wide popular support.

Once Hitler was Chancellor it didn't really matter what the law was, or had been. He had vigour, energy and the simple willingness to use brute power on his side. The Depression-hit Weimar politicians couldn't match him. And though it is an extreme example, there are plenty of others. The Stalin Constitution of 1936 was regarded by many outsiders as a model of liberalism, with its guaranteeing of voting rights and liberties. But it was ratified just as the Great Purge was getting under way - where many thousands of citizens (all with full voting rights) were sentenced to instant execution by secret tribunals. Nor, as I recall it, was it strictly legal under the laws of Rwanda for Hutu militias systematically to kill their Tutsi neighbours with gun and machete.

I am not saying anything as crass as that it doesn't matter what the government does, as long as you live in a liberal democracy. What I am saying is that, if you don't have a liberal democracy, everything else goes to hell. And it does strike me that, right now, we are in a nasty phase of attacking democratic politics and its inevitable representatives, the politicians, for their deficiencies and taking refuge either in populism, legalism or magical thinking.

Any of these are dangerous, but doubly so in a time of potential depression. The populism is expressed in the casual, jokey bracketing of politicians with fraudsters, the influence of potty-mouthed right-wing bloggers on some political journalism and an impatience with foreign workers and other minorities. The legalism is evident in the suggestion that politicians should hive off their responsibilities to technocratic bodies, such as an “independent” NHS. The magical thinking comes in imagining wheezes that would somehow save us from the messy business of having, joining, organising, funding or voting for political parties.

It always amazes me - and it shouldn't - how clever adults seem to believe, against the evidence of their own experience, that the governing classes in our democracy inevitably mess everything up. “National politics is discredited. The wrong people are in power. The whole system is broken”, asserts a high-brow Establishment figure at the weekend, listing the Child Support Agency, cost overruns and failures of IT projects, the fiasco of the new contracts for doctors and dentists, the “late marking of SATs” the loss of personal data, as definitive proof.

But what about (and here, as a scribbler, you take a deep breath because you know what's coming) the things that went right? The new schools. The defeat of bullying. The new hospitals. The waiting list reductions. The expansion of nursery education and of parental rights. The city regeneration. The Right to Roam. The many public sector IT projects that - quietly - worked. Northern Ireland. Were these all done by the wrong people and despite the broken system? So, in a messy adult democracy you get achievements and you get stupid errors.

So how depressing it is that there are Grand Conventions in defence of liberty and none in defence of politics; that we count cameras but won't join parties; that we obsess about biometrics and databases and refuse our support to the democratic politics that is the real safeguard against authoritarianism or chaos.

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