If John Alexander had been a British citizen when Australia's constitution was adopted in 1901, his position as an Australian parliamentarian would surely have been perfectly safe.
There were no Australian citizens in 1901 ??? or for the next half century.
The founding fathers, in short, would have been altogether confounded by today's uproar about dual citizenship concerning those who might be declared British.
Most Australians until 1948 were simply British subjects, owing their allegiance to the British crown.
It wasn't until the Nationality and Citizenship Act 1948 (later renamed the Australian Citizenship Act 1948 and replaced by the Australian Citizenship Act 2007) that Australians could call themselves citizens of their own country, though they continued for decades to be "British subjects".
The constitution's section 44 (i), which is causing all the current heartburn, would originally have considered a nonsense any concern about a parliamentarian who was - as John Alexander may be - a British citizen.
The section declares anyone incapable of being chosen as a Senator or Member of the House of Representatives if they are "under any acknowledgment of allegiance, obedience, or adherence to a foreign power, or is a subject or a citizen or entitled to the rights or privileges of a subject or citizen of a foreign power".
The Australian Constitution then, might be read - in the first half of last century - to have defined a "foreign power" as a power outside the British Empire.
Indeed, in 1946 a sore loser for a West Sydney seat, a fellow named Ronald Sarina, complained to the High Court that the winner, William O'Connor, was under allegiance to a foreign power because he was a Roman Catholic. The complaint, sensibly, was later withdrawn. A similar complaint four years later was thrown out by the High Court because it would be unconstitutional to impose a religious test on candidates.
To make things a bit more difficult for those trying to make sense of this old document, you will not find a requirement that an Australian parliamentarian must even be an Australian citizen (because, of course, when the constitution was written, there was no such creature).
It has been up to lawmakers since to make citizenship a statutory, rather than a constitutional, requirement for election.
The upshot, anyway, has been that the High Court has taken to interpreting section 44 (i) as outlawing dual citizenship - which includes British citizenship - for Australian parliamentarians.
It seems anachronistic to those who look beyond our borders - the UK, Canada and New Zealand, to mention only those with similar parliamentary roots, do not prohibit dual citizens from public life, and nor does the US Congress.
John Alexander, putative Britisher, must be cursing his rotten luck for having entered parliament 70 years too late.
And Malcolm Turnbull, whose entire government is in jeopardy because of a constitution written before Australians held their own citizenship, must simply be cursing.