Curiously enough, the proponent of this policy, Evan Thornley, is not a religious right-winger, but a member of the Fabian Society, that very Britishly pragmatic socialist organisation which once had George Bernard Shaw as one of its members (and, during the Cold War, was accused by Bircher types of using its shadowy influence over the Labor Party to implement "Sovietisation by stealth").
There are, of course, numerous problems with this proposal. Were it to be adopted, politicians would start bidding for the votes of large families by giving them more money, taken by punitively taxing the suddenly all-but-disenfranchised non-breeders. (What are they going to do, vote for someone else?) This would result in a system which effectively regards not having children as deviant behaviour to be penalised; once this is a matter of bureaucratic fact, the culture would soon follow. And then there is the likelihood of a bias towards large families bringing with it a bias towards religious conservatism; all of a sudden, Victoria would look like the repressively paternalistic 1950s white-picket-fence dystopia John Howard didn't quite succeed in building.
Of course, that's if such a policy were ever adopted. There are practical problems with implementing it, such as deciding which parent gets their childrens' votes. Granted, they could be split in half (with each parent in the 3-child family having 2.5 votes), though this proposal effectively changes the paradigm of democracy, from one comprised of voting individuals to one comprised of voting families. It has echoes of the top-down "strict-father" model of the family so favoured by conservatives, and at the heart of the culture war in America and Australia: it reinforces the idea of a family being defined by a chain of authority residing in the head of the household. Granted, it does not define a head of the household, though it is a short distance from accepting the paradigm that votes are allocated per household, and not per individual, to accepting that the votes for all members of the household are cast by the head of the household.
Mind you, given that Thornley's boss has suddenly resigned, this proposal is likely to be even more dead in the water than it was before. Unless the Howard government decide that it has battler-rallying potential and put it to a referendum, or else Rudd decides to use it to outflank the family-values warriors on the right.
Then there's this: http://www.isteve.com/babygap.htm
Having kids may not make people more (politically) conservative, but particularly large families tend to be correlated with hardline religious convictions of the sort that go hand-in-hand with right-wing politics. Giving more votes to people who have more children is likely to shift the balance of power towards conservatism. Even if most people with children are politically indistinguishable from the childless, the small minority of Hillsong/Assembly of God types with large families and hardline religious-right leanings will still get a lot more influence (one such family may have the votes of 2 or 3 average families and three times as many single people).
Let me just add that this idea is hardly 'uniquely' Australian (thoug to what degree it is typically Australian I dare not judge); German conservatives have been toying with this idea for years, and it infrequently pops up in other continental European countries as well. The German wikipedia even has an article dedicated to the Toddler Vote: http://de.wikipedia.org/wiki/Kinderwahlrecht
Thanks for that, mvg; I didn't know that. It's interesting that in Germany, it's the conservatives who are for the idea, whereas in Australia, it's "progressive" Fabian Socialists.
I think it's a myth to assume having kids will make you more conservative.