There is truth. One of the reasons for our current disastrous plight is that politicians, especially but not only on the Thatcherite Eurosceptic right, have come to feel that what is true is what they believe. Their beliefs may not correspond to reality but that does not matter. Others may think they shamelessly lie or deceive, but what matters is an intent to be truthful to their beliefs, even if the gap between what they say and what is true is so yawning anyone else would regard their utterances as bare-faced lies.

Esther McVey is a passionate Thatcherite believer and fully paid-up Eurosceptic – crucial attributes for success in today’s Conservative party. But her faith is a closed, druidic belief system that, whatever its dubious merits 40 years ago, now has no relationship with today’s economic and social realities.

She is work and pensions secretary, charged with delivering the biggest change in the welfare system for more than half a century – consolidating six income-based benefits and tax credits into one: the universal credit.

There were good arguments for trying to simplify the system – one means test rather than many – but the reality is that it was complex because the lives and circumstances of Britain’s tens of millions of very poor people are also complex. But the belief of the Thatcherite architects of universal credit, notably Iain Duncan Smith, was that the complexity was encouraging claimants to game the system, creating a dependency culture and making poverty worse not better. Best consolidate the six benefits into one in the name of simplicity – making it available only to those in desperate and obvious need who cannot pass the tough availability-to-work tests – save billions in welfare payments and end the dependency culture.

In his and now McVey’s mind the intent was what mattered – even if it is obvious that reality means that universal credit is de facto a regression to the Victorian poor laws, offering a mean, inflexible payment to the “deserving” poor and varying degrees of destitution for the rest.

Last week reality closed in on McVey. The independent National Audit Office (NAO), beleaguered custodian of reality, has a responsibility to tell the truth. Its report last month was damning. Not only was the system operationally faulty, but pilots showed that many claimants were worse off, with a significant minority not receiving any benefit at all. It should not be extended until these faults were remedied. What’s more, it did not promote employment and was not value for money.

Amazingly, McVey told the House of Commons, under questioning, that the NAO, notwithstanding its criticisms, wanted the rollout of universal credit to be accelerated. Last week Sir Amyas Morse, auditor general, published an open letter to her. The NAO had decidedly not said that. Rather, it had suggested the opposite: a pause while the issues it raised were addressed. He wanted the record set straight. Two hours later, McVey apologised to the Commons for misleading it. But she made no commitment to address the new system’s deep faults.

It was shameless, a degradation of our public life. But sealed in the bubble of her ideology, protected by a rightwing press locked in the same bubble, she was able to get away relatively unscathed – despite Labour calls for her resignation. She may have overtly lied: but the greater integrity, she will have told herself, was to be truthful to her beliefs.

The same shamelessness abounds across the Eurosceptic right. Dominic Cummings, former director of Vote Leave, has refused to give evidence to the House of Commons media select committee over alleged illegal conduct during the Leave campaign. Why should he appear before a committee interested only in “grandstanding”, cocking a snook at parliament? The only legitimate reality is his reality: to be asked questions that might expose it to be a lie, even by elected parliamentarians, is inadmissible. Like McVey, his integrity lies in being loyal to the presumptions of his belief system.

In this universe there can be no shame. To feel shame, as the great philosopher of ethics, Bernard Williams argued, you have to feel that you exercised your will to choose a course of action in a way that transgressed shared moral norms. McVey and Cummings cannot feel shame because they worship a different God and moral code. They felt compelled to do what they did: to impose universal credit or leave the EU are higher callings, whatever the results.

Nor is this deformation the preserve of the right. Jack Straw has remained silent over Britain’s involvement in rendition and torture. The greater god was obeisance to US foreign policy and the “war” against jihadist terrorism. There was no choice. Hence no shame.

But reality will out, even for those who feel no shame. The destitution invoked by universal credit, the disclosure of torture, and the carnage of a hard, no-deal Brexit are realities whose truth cannot be dodged. The Leave campaign was particularly shameless: loyalty to a set of impossible propositions and falsehoods triumphing over fact, leading inexorably to a first-order national crisis.

For all today’s celebration of strongman politics and denigration of democracy as compromised and weak, democracy’s great strength is that it exposes our governors to reality. We live in societies with shared core moral norms. We have values that guide our conduct, but they cannot trump what is real and true. One of the reasons for the national celebration of Gareth Southgate, the England manager, is his integrity: he combines proper ambition for his team with a strong sense of football truth – so refreshingly different from the rest of our national conversation.

Ultimately, as Brexit’s leaders and Thatcherite ultras are learning, democracies find you out. Boris Johnson and the contemptible Brexit leadership may feel no shame, but they – even though they do not own it themselves – are shamed. Being truthful to a closed belief system does not work in a democratic society – on either left or right. The great politician marries values, beliefs and practical action – and lets us know they can feel shame. We sorely need them back.

• Will Hutton is an Observer columnist