In 1867, constitutionalist Walter Bagehot decoded the enduring magic of Britain’s royal family: “Its mystery is its life. We must not let daylight upon its magic.”

Just over 140 years later, last Saturday night the current queen’s favourite child, apparently, and certainly her dimmest, invited not daylight but the bright klieg lights of the BBC’s Newsnight into Buckingham Palace.

Prince Andrew ignored Bagehot’s warning; apparently he ignored all advice to the contrary. He thought a 50-minute sit-down with the polite but piercing Emily Maitlis would put to rest the storm around his cavorting, and worse, with the disgraced and now dead US financier and convicted paedophile Jeffrey Epstein.

Clueless about the currents of empathy and sympathy for victims of abuse, Andrew offered a clumsy explanation for continuing his relationship with Epstein – his “tendency to be too honourable”.

He was also utterly unconvincing in his denials of a sexual relationship with 17-year-old Virginia Roberts Giuffre (he was at a pizza joint in unroyal Woking on the night). Far from reducing the heat on the prince, who apparently is incapable of perspiring, the flames only intensified. And threatened to immolate the royal family itself.

On Monday, an online poll by The Times asked: “Should Prince Andrew retire from public life?” Within four days, 86% had answered affirmatively. By Wednesday evening, caving to public pressure and deserted by sponsors who had backed his public philanthropies, the prince and the palace issued an unprecedented statement that he was “standing down from public duties for the foreseeable future”.

The third season of Netflix’s The Crown was screened just 24 hours after the real-life Andrew interview. The enjoyable TV confection was warmly received. Andrew’s interview, however, was judged by a former palace press secretary to be “not so much a car crash but an articulated lorry crash”.

Step forward here, one Makhosini Mgitywa, spokesperson for the department of human settlements and, given his recent appearance, no mean court jester himself.

It is perfectly true that he had an impossible brief: defending the appointment of the disgraced Bathabile Dlamini, restored to public office by an unofficial member of our local royalty, Lindiwe Sisulu.

Mgitywa offered two nuggets of incomprehensibility on the minister’s decision to appoint Dlamini to the chair of the social housing board. First, she has “institutional memory” (of misgovernance, criminality and perjury, by all accounts) and then the zinger: “She is a black woman who represents the demographic of poverty . which is black and female.”

Even in the mad universe of bad defences, this River Ganges of a justification that washes away all sins simply collapses on its face. It is beyond parody that a disgraced former minister who ran up R11,000-a-night hotel bills, extorted R1m from the Treasury to pay for private security for her children and was found by the Constitutional Court to be “reckless and negligent” can be anything other than a “representative” of gross misconduct.

Then again, back in 2006, then speaker of parliament Baleka Mbete arranged a cushy plea bargain which allowed Dlamini to be criminally convicted of defrauding parliament of R250,000 of travel and escape with a fine.

And Mbete had her own car crash in a recent TV interview with Al Jazeera. She claimed to be unaware of corruption and the metastasising crime in the country; neither she nor her ruling party bore any responsibility. “The colonialists brought crime from Europe to Africa,” she offered an incredulous live audience in October.

Modern-day chronicler of public life Matthew Parris, a former Conservative politician, noted that “being a politician feeds your vanity and starves your self-respect”. And in the cases of Prince Andrew, Lindiwe Sisulu and her spokesperson, and Baleka Mbete, it also erodes common sense.

Leon, a former leader of the opposition, now chairs Resolve Communications.

Featured in The Sunday Times