Just as no one has “ever lost money by underestimating the intelligence of the great masses” — according to HL Mencken — so no psephologist has ever gone wrong by underestimating the intelligence of the Victorian Liberal Party.

Yesterday the Liberals shot themselves in the foot in spectacular fashion by putting the ALP ahead of the Greens on their above-the-line preference distributions for the Legislative Council. (The group voting tickets are all available on the VEC site, but they’re hard to find; Antony Green has a much more user-friendly version.)

What does this mean? On 2002 figures (these are Antony Green’s calculations), assuming that, as in the past, both major parties preferenced the Greens ahead of each other, the result would have been Labor 20, Liberal 14, Greens five and Nationals one.

Liberal preferences going to Labor instead would transfer two of those seats – in Eastern Metropolitan and Western Metro regions – from Greens to Labor, making it 22-14-3-1.

The Greens could still win in those two regions if there is a significant swing to the Liberals (so that it’s Labor preferences that get distributed), just as they could win in South Eastern Metro if the swing goes the other way. Only in Western Victoria, which would have been line-ball on 2002 figures, does the preference move seem to have doomed their chances.

On the other hand, the Greens seat in Eastern Victoria region is highly precarious, since even a small anti-Labor swing would give it to the Nationals. But the Greens should still win seats in Northern Metro and Southern Metro, unless their vote falls sharply from 2002 levels.

So the move is quite likely to deliver the worst of both worlds for the Liberals: a continued Labor majority in the upper house, with no checks and balances, plus a still-substantial contingent of Greens who will be out for revenge. The 11 Liberals in marginal seats must be wondering what their leadership was thinking.

Why did they do it? It could be pandering to big business, along the lines of “if we give them the untrammelled Labor government they want this time, maybe they’ll give us more money to help defeat that government next time” (yeah, sure).

Or it could be just a basic failure to understand the voting system, thinking that screwing the Greens will somehow help the chances of more sympathetic groups like Family First (it can’t, because these preferences can only be counted when those other groups have been eliminated).

Most likely, it was just a temper tantrum, since on all accounts the Greens had been painfully difficult to deal with. But that’s why temper is such a problem; you end up doing things that hurt you more than your intended target.