For Malcolm Turnbull, the harsh political arithmetic around Barnaby Joyce points to an inconvenient truth.

Perhaps the final element to be factored in is time - playing for which is the standard defence in politics.

The "best retail politician in the country" has always been an expensive "asset" - his backblock popularity offset by gaffs and questionable judgments. Think remaining in cabinet when not constitutionally elected; relocating public service functions to his electorate; taking (initially) a $40,000 cheque from Gina Rinehart; and that inland rail boondoggle.

Now however, Joyce finds himself at odds with his own base - although colleague Nigel Scullion said constituents described it more as "a bit of a pickle". Joyce's private decisions are a public talking point, the government's biggest distraction, his party's sharpest liability.