WHEN I am supreme dictator of the universe, Holocaust-denial will still be a crime, but as part of a wider ban on all mention of German politics between 1933 and 1945. Usage in public of the word "Hitler" will be prohibited by law. Careers will be extinguished by one careless word. Had these laws been in effect this week, we would never have heard any more from Lord Carey or Professor Hans Küng.

In an interview with Kate Connolly of The Guardian, Professor Küng compared an oath that bishops take to the Pope to one taken to Hitler. Perhaps things are different in Ger­many, but over here that seems to me to be among the things that you simply cannot say about a German Pope.

Professor Küng is quoted as saying: "The uncon­ditional obedience demanded of bishops who swear their allegiance to the Pope when they make their holy oath is almost as extreme as that of the German generals who were forced to swear an oath of allegiance to Hitler."

There's no point in blaming the journalist for printing something so juicy. Of course, the Professor is right that the papacy is an auto­cratic institution. Of course, he is right that since 1979 no one who has expressed in public doubts about Humanae Vitae has been made a bishop.

"The Vatican made a point of crushing any form of clerical dissent. 'The rules for choosing bishops are so rigid that as soon as candidates emerge who, say, stand up for the pill, or for the ordination of women, they are struck off the list.' The result was a church of 'yes men', almost all of whom unquestioningly toed the line."

But no one is going to remember that. He used the H word and touched the live wire.

Similarly, Lord Carey, at a fringe meeting at the Conservative Party Conference to oppose gay marriage, had to drag Hitler into his dis­comfort.

"Asked about opponents of gay marriage being described as 'bigots' - on one occasion by Nick Clegg, the deputy prime minister - Carey said: 'Let us remember the Jews in Nazi Germany. What started against them was when they started to be called names.

"'And that was the first stage towards that totalitarian state. We have to resist them. We treasure democracy. We treasure our Christian inheritance and we want to debate this in a fair way.'"

This is so mind-boggling that there can be no question of misquotation. It drew an excoriating riposte from one of The Guardian's science bloggers, Martin Robbins, about what it was like to be a gay man in a concentration camp under real Nazis. I am not going to quote that, because the details of one execution are ghastly.

The irony of it is that there have been and still are plenty of opponents of gay marriage (among them Michael White, who wrote The Guardian's report) who are not in the least bit bigoted. There are plenty of proponents of gay marriage who are violently and unreasonably opposed to Christianity and anything else they can recognise as religion. But once you play the Hitler card, you lose.

Besides, you can't really claim to be in favour of English democracy and opposed to brutal and unfair invective. When Nye Bevan called the Tories "lower than vermin", he caused a great deal of pain and real in­dignation, but I don't believe anyone on the other side suggested that the Nazis had started off by calling the Jews names. Things were dif­fer­ent in 1947, when memories of real Nazis were still fresh and vivid.

Democracy gets more complicated even than that. It is quite possible that the sense of be­trayal, and of having his country removed, which Lord Carey feels is pre­cisely what David Cameron wants him to feel. The calculation is purely demographic and electoral. There may be plenty of Lib Dems and Labour types who want to stick it to the Church of England on principle. Mr Cameron is not one of them. But Lord Carey is operating on the far side of a cultural divide from almost everyone un­der 40. They cannot see what all the fuss is about.

They are also going to have a thoroughly mis­erable time, econom­ically. What better way for the Conservatives to show that they are on the same side than by upsetting a lot of grouchy old people hung up on a forgotten and now incomprehensible past?

Of course, small-c conservatives wouldn't think like that at all. But they don't win elections nowadays, and they don't run the Conservative Party, either. Perhaps we ought to suspend the Reichstag, oops, I mean Parlia­ment, if we want to save marriage.