Well the story is now developing into they had Green cards during his first year as chancellor, so in theory they must have been paying US tax on international earnings.
However the most likely thing is she's been funnelling her money off to a tax haven, as do most non-doms. Something that was dodged in their statement to the press.
I don't think the debate here should be whether non-dom status is right or wrong to exist, that's far too wide and far reaching a subject.
It's that the associated benefits of being in a marriage with a globe trotting international non-dom is 100% incompatible with the office of Chancellor of the Exchequer of the UK, and it's even more mind boggling when said chancellor putting taxes up during a cost of living crisis.
He's absolutely cooked as Chancellor and he'll never be PM now.
Agree 100% people can't expect him to give up his wifes citizenship, but he will have to give up his ambitions of holding one of the 4 great offices of state.