When did there get to be so many cavaliers and so few roundheads?

The Queen's Diamond Jubilee kicked off on Monday with a trip to two schools near Sandringham where Her Majesty was regaled with a play about her "60 glorious years" and a witty display based on Nic Allan's irreverent picture book The Queen's Knickers. Would unfettered tots break the rules by inquiring about their monarch's undies? No. They were "good as gold", especially four-year old George Bushell-White who, according to one newspaper, showed "that chivalry is still alive" with his "magnificent waist-down bow". Even the London title which memorably devoted one paragraph to the nuptials of Charles and Di, gave it a whole page.

Now we are in for months of undiluted monarchist pageantry and revelry whooshing us all (well, most of us) down the Thames on a tide of patriotic fervour towards the London Olympics.

Don't get me wrong. I think the Queen is a good sport. I admire her doggedness and her sense of duty and loyalty, two rather unfashionable virtues these days. That's the problem really. It's impossible to have a sensible dialogue about the future of the monarchy without it being construed as an attack on a pint-sized octogenarian who can't fight back.

There's no pedigree for my republicanism. Perhaps it has its roots in an excess of covering royal visits where she seemed as bored as I was. Perhaps it's because every royal occasion seems to lurch between the sycophantic and the saccharine.

My parents' generation, mindful that the Queen's parents stayed in London during the Blitz and visited the bombed-out East End, would have died for her. It's no coincidence that there were four Annes in my 1950s infants class and four journalist Annes at The Herald two decades later. My children too are monarchists in that cheerfully Cath Kidston post-modern designer sort of way. During last year's royal wedding they turned the lounge into a blizzard of red, white and blue, interspersed with cardboard cut-out corgis, while I sat sullenly on the sofa in my black Not the Royal Wedding T-shirt.

When did abolishing the monarchy become such a taboo subject? In the early 1990s when Charles and Di were squabbling, a majority of British people believed the monarchy would be history in 50 years. In 1994 the right-of-centre Economist came out in favour of a republic. In the same year a poll of Labour MPs found 40% wanted a republic, either immediately or when the Queen dies. The Liberal Democrats debated the issue at their party conference.

Bizarrely, it was the death of Diana, initially handled so badly by Buckingham Palace, that turned the tide. The epic proportions of the public emotional catharsis that followed effectively hobbled for a generation even soft republicanism like mine. Carefully choreographed glimpses of the Royal Family's private lives enabled them to ride the wave of an emerging celebrity culture.

If Posh and Becks seemed exotic and exciting on their pretend golden thrones, they weren't a patch on the real thing. And this was a soap that would run and run in the full glare of the media. So what?

Why did the whole Wills and Kate thing make me vaguely queasy? It wasn't merely that it seemed a handy distraction for the Coalition Government while it was busy dismantling the NHS in England and ripping up social security. Rather, the whole business of princes marrying commoners and pulling them on board a bandwagon of staggering wealth and privilege creates an illusion of social mobility. In fact, the monarchy represents the exact opposite. It personifies the entrenchment of the class system with its associated ludicrous expenditure and perks while nearly three million British people are unemployed and millions more live in poverty. It represents the medieval power structure, based on aristocratic privilege, where one's position in society is determined by birth rather than hard work, talent or democratic mandate.

More generally, in a spurious way, the monarchy legitimises the growing inequality of wealth and opportunity and by its pleasant apparently-inclusive nature, suppresses dissent. Will Hutton, one of the few commentators to address the issue, worries that "we are so accustomed to the presumption that democracy works that we have become blinded to the re-emergence of pre-democratic values".

Scottish Nationalists have tied themselves in a curious knot on this issue. In 1998 a survey of 128 SNP candidates for the first Scottish Parliament found that half of them were republicans. Only 29 would retain the monarchy. Yet today Alex Salmond gives the impression of being the Queen's most loyal subject. And the party, wary of undermining support for independence, has quickly dumped republicanism and promised voters that the sovereign would remain the head of state in an independent Scotland. Meanwhile, we live with the contradictions, such as English rugby fans singing God Save the Queen, while Scottish ones would send "proud Edward's army home to think again".

Ultimately, it may be other constitutional changes that shift public opinion. Once all the hereditary peers have gone from the House of Lords, the Prime minister's powers of patronage, exercised in the name of the Crown, must come under scrutiny. The reform of the constitution and the monarchy are interdependent. Can Britain be a true democracy when there is only one candidate for the next head of state and nobody has a vote?

Say it softly but Charles may be the most valuable asset to the republican cause. Instead of proclaiming Charles king when the time comes, it would be relatively simple to refer the succession back to the House of Commons, which could then begin construction work on a truly democratic constitution. The royals could continue to live here but the wealth and buildings held in the public name would be removed. Not lèse majesté. More a question of less majesty.