There’s been much beard-stroking in the media coverage about why senator-perhaps Matt Canavan is a special case compared to former senators Scott Ludlam and Larissa Waters, so it’s fair that, instead of resigning, the High Court should consider his position. It’s more of the charmed media life that Canavan seems to lead. His extremism on coal (he called for a boycott of Westpac for not wasting enough shareholders’ money on unviable coal projects) and on abortion (he stood up for the rights of those nutjobs who harass women outside reproductive health clinics) rarely seem to get mentioned in media coverage. Instead, Canavan is portrayed as an energetic rising star of the LNP. And now, here he is, a victim of his mother’s application for Italian citizenship — he didn’t even know and he’s never even been there. Surely it’s just a minor hurdle in his ever-upward career trajectory? Not like those sloppy Greens senators.

In fact, Canavan’s case compares poorly with those of Ludlam and Waters. They, too, didn’t know they were citizens of New Zealand and Canada, respectively, courtesy of their parents. Ludlam at least was a kid when he was brought by his family to live in Australia, where he was naturalised as an Australian. He can remember being in New Zealand. Waters was a baby, the child of Australians temporarily in Canada who moved back home soon after. Waters acquired Canadian citizenship like you’d pick up a cold while travelling. Indeed, the relevant Canadian laws were changed just after her birth — as the law stood when she was born, she wouldn’t have been a Canadian, but the new law was retroactive.

Canavan, however, can’t blame being a baby or a kid. He was an adult, in his 20s , when in circumstances that are difficult to quite work out, his mother acquired Italian citizenship — possibly something to do with Canavan’s father pleading guilty to a major theft — and in doing so, somehow, acquired it for him as well.

[EXCLUSIVE: every single Greens member has just resigned]

All three cases illustrate that section 44 of the constitution is so broadly cast, and so widely interpreted, as to be absurd — three capable politicians who are Australian citizens, who weren’t even aware they “owed allegiance” to another power (as it turns out in the case of Ludlam and Waters, exactly the same “power” as the one that rules over us), who acquired or retained citizenship in circumstances they had no awareness of, who can’t do their jobs because notionally they’re in the thrall of some rival state.

But only one of those has decided not to cop it sweet, but to call in the lawyers, at government expense, to save himself. In retrospect, there was a certain refreshing quality to Ludlam and Waters declaring they’d screwed up and were quitting. Both made clear the fault was theirs and theirs alone. “This is on me,” Ludlam said. “It was my fault and my fault alone,” Waters said. And they went.

[Poll Bludger: who will replace Scott Ludlam?]

It’s so rare to hear that in politics now. In an era when ministers refuse to take responsibility for even the most egregious debacles in their portfolios, when public servants who’ve committed appalling blunders hide behind “we’ve learnt valuable lessons” and dodge estimates questions under ministerial cover — in short, when responsibility has become a nebulous quality that exists in the abstract (“I take full responsibility”) but never has any actual consequences — someone saying “I messed up, so I’m quitting” is like a gale of fresh air.

But not for major parties, it seems, and not for ministers. They might mock the Greens for their “extraordinary sloppiness”, but it’s a different story when they’re caught out. It’s not even fair to single Canavan out, really — standing next to him yesterday at his media conference was George Brandis. How many times has Brandis comprehensively stuffed up, in ways that even according to the current abysmally low standards of ministerial responsibility he should be sacked, and then deployed some elaborate, nonsensical, justification for why it wasn’t his fault? At least Canavan had the grace to quit the ministry — Brandis didn’t even do that after he misled the Senate.

Wondering why voters are so disengaged with politics and so suspicious of the political class? Politicians keep serving up any number of reasons, but the failure to take responsibility is up there, too.