Parliamentary democracy – Britain’s great gift to the world – has gone bad. It has putrefied into brute populism. The 24-hour media cycle forces politicians to respond to every trifling issue and act on every interest-group demand, no matter how overblown. The more they do so, the more government pervades and controls citizens’ lives. Then, as the role and power of government expands to accommodate this widespread pervasion and control, the more largesse and patronage it has available to disperse, so the more supplicants it attracts and the bigger the political class that feeds off it.

In this downward spiral, principle is abandoned to pragmatism: politicians indulge every populist cause that might prolong their term in office, power accumulates unchecked, and the democratic rights and liberties of minorities – and of the mute majority – are trampled underfoot.

Politicians even seem to think that they can amend our very constitution by a simple majority vote in Parliament. Witness the remarks of UK Deputy Prime Minister Nick Clegg that a reform of the House of Lords does not need a referendum and the onus is on those who believe otherwise to make the case for it. That really is a breathtaking ignorance about the principles of democracy and the rule of law. There may be a lot wrong with the House of Lords, right enough. But by that argument, a majority in Parliament could at a stroke abolish any democratic institution, void any established civil right, and declare itself a dictatorship. As Ayn Rand put it:

Individual rights are not subject to a public vote; a majority has no right to vote away the rights of a minority; the political function of rights is precisely to protect minorities from oppression by majorities – and the smallest minority on earth is the individual.

Politicians' powers come from us. We might well be prepared to accept some curbs on our activities on the grounds that it will, on the whole, produce a better-functioning society. But none of us would willingly give a majority the power to exploit and abuse us. That is why we cook up complicated voting and parliamentary systems – not to choose and empower our representatives, but to limit them, to restrain them and to be able to get rid of them. Sure, a history full of accidents and entrenched power means that those institutions are far from perfect, but it should be up to the whole electorate to decide how they should be reformed. Allowing parliamentarians to design what parliament should look like is akin to putting the cat in charge of the cream jar.

Perhaps it is already too late. Even the much-feted US constitution has been unable to prevent politicians expanding their role, their power and their budgets. It seems we have overthrown the tyranny of monarchs, only to enslave ourselves under a new tyranny of elected dictatorships. And the trouble is that we ourselves connive in this tyranny. We demand favours and subsidies for our pet causes, one after another after another. And – in a sort of political version of Say's Law – government simply expands to meet that demand.

The West shook off the control of the old aristocratic class through a worldwide wave of revolutions. We need a new worldwide wave of revolutions – constitutional revolutions – to save ourselves from the new tyranny of the political class. As I explain in my primer on public choice economics, we need voting systems that prevent interest-group capture of the policy agenda. Rules to stop minorities being exploited. Limits on what politicians can do. Curbs to end political careerism. Ceilings on government’s power to spend, borrow and print money.

And we need a revolution in understanding: reminding ourselves and the likes of Nick Clegg and other MPs that democracy is not merely the dictatorship of the majority, but the vital mechanism by which dictatorship of can kind can be thwarted.