How’s this for some electoral maths.

There’s just one seat between Labor and the Liberals in South Australia — 22 to the Libs; 23 to Labor but short of a majority. Two independents can give either side government, but one of them, Bob Such, falls sick and may never return to Parliament. As William Bowe writes, the agonising question for independent MP Geoff Brock was thus:

“… Such’s health issues left the Liberals high and dry, as Labor would have commanded a majority on the floor regardless of whether the Speaker’s chair was filled by a Liberal or by Brock.

“Consequently, the alternatives facing Brock were a Labor minority government, or parliamentary deadlock and a fresh election. Much as opponents of Labor and/or minority government in general might complain that the latter is the preferable option, they have no reason to suppose the result of a second election would be any different from the first.”

Good luck with that. Brock’s decision — to accept a cabinet post and award Labor a fourth term in government — was perhaps the only viable one. A legitimate deal was done and Labor Premier Jay Weatherill wins fair and square.

But the people of South Australia — a large majority of whom voted Weatherill out — will feel cheated all the same.

Legitimacy will be Weatherill’s biggest challenge over the next four years — not in the eyes of the Parliament, but in the eyes of the people.