Anyone seeking political office should have their nation at heart. It is reasonable to expect that they would know the laws of the land and be committed to following and enforcing them. Australia’s deputy prime minister, Barnaby Joyce, and others in the federal parliament therefore only have themselves to blame for ignoring nationality requirements laid out in the constitution. Their disqualification from office by the country’s highest court has nothing to do with political mudslinging, but their own failures and those of their parties to read and abide by the rules.

The downfall of the politicians followed revelations that they had dual citizenship, relatively common for a nation built on migration. But the constitution prohibits people who are citizens of another country from seeking election to high office. Joyce was born in Australia, but his father was from New Zealand, a country which gives automatic citizenship by descent at birth. In the cases of the three others who have lost their parliamentary seats and the two who earlier resigned, there were varied circumstances, among them having been born overseas and failing to renounce the citizenship of that country.

Joyce’s disqualification strips the governing Liberal Party coalition of its one-seat majority in the lower house of parliament; that the opposition Labor Party drove the citizenship issue made it seem to some Australians to be purely about political point-scoring. One argument was that Joyce was unaware that he had dual citizenship, a mute matter given that when faced with reality in an announcement in August by then New Zealand opposition Labour Party leader Jacinda Ardern, who has since become prime minister, he renounced his citizenship of that country. Her revelation was bound to deepen the crisis, prompting Australia’s foreign minister, Julie Bishop, to make accusations of overseas meddling in politics.