In part 1 we noted that the United States constitution requires seats in the House of Representatives (and therefore in the electoral college) to be apportioned among the states according to their total population. Australia has the same system: section 24 provides that “The number of members chosen in the several States shall be in proportion to the respective numbers of their people.”
What about the other use of population statistics, to draw actual electoral boundaries within states for either state or federal elections? Are they done on the same basis?
Well, no. All Australian electoral boundaries are drawn by independent commissioners, and all of them try (to a greater or lesser extent) to equalise numbers between electorates, either at the time or in the near future. But the number that they work with is the number of enrolled voters, not the total population.
That means that non-citizens, children and people who have failed to enrol, although they count for the purpose of determining how many seats their state gets, don’t count when it comes to drawing boundaries. But if you enrol but don’t vote, you still count for both.
In 1974 the Whitlam government proposed a constitutional amendment to change this and force total population to be used as the basis for drawing boundaries. This would have worked to Labor’s political advantage, since areas with more children and immigrants, which tended more to be Labor-voting, would get more seats. But it was defeated in the referendum, winning a majority in only one state, New South Wales.
The difference leads to some anomalies. If seats were apportioned according to numbers of voters rather than population, South Australia would gain an extra seat, while Queensland, Western Australia and the Northern Territory would each lose one.
But fundamentally the differences are small. Because we have compulsory enrolment and compulsory voting, enrolment numbers are not a bad proxy for both voters and population, or at least voting-age population.
In the US things are different. Enrolment and voting are both optional, and enrolment procedures vary widely from state to state. Using enrolment numbers as a guide to drawing boundaries would be fraught with difficulty.
It’s probably safer to stick with population, which in fact is what the American states all do. But the Supreme Court has shied away from saying whether that is constitutionally required: it has forced states to equalise numbers between districts, but left open the question of exactly which numbers it’s permissible to use.
In 2015, conservative activists in Texas sued the state in an attempt to force it to use voting-age citizen population rather than total population as the basis for drawing state legislative boundaries. The Supreme Court in Evenwel v. Abbott unanimously rejected the claim, but deliberately avoided a decision on the constitutionality of such a move.
Texas in 2016 had an estimated total population of about 28.7 million. But in the presidential election held that year, only a little over 8.5 million Texans cast a meaningful vote. Between those two very different figures lie a wide range of possible numbers that could be used to draw boundaries, all with slightly different effects – and in a close election, even slight differences can be important.
Just as the 1974 proposal in Australia would have benefited Labor, a move in the opposite direction in the US would work in favor of the Republican Party. There would be fewer seats in big urban areas that vote Democrat, and more seats in places with fewer children or immigrants.
Although that would be bad for the Democrats, it’s less clear that it would be bad for democracy. Justice Clarence Thomas, in Evenwel v. Abbott, said that “There is simply no way to make a principled choice between interpreting one person, one vote as protecting eligible voters or as protecting total inhabitants within a State.”
But why stop at eligible voters? Why count those who are eligible but choose not to enrol? Or who enrol but choose not to vote? Or who vote informal?
The current conservative majority on the Supreme Court has already shown that it likes to leave this sort of decision up to the states; last month, in Rucho v. Common Cause, it refused (by a 5-4 majority) to interfere even with blatant gerrymandering – which can do far more to distort outcomes than tinkering with the population figures.
As Matt Ford argued in the New Republic last week, Republican politicians will probably take that judicial restraint as a cue to move away from using total population, at least for state-level boundaries. And given Australia’s lack of constitutional guarantees, it’s even less likely that our High Court would interfere if a state were to switch the other way and use total population, or pretty much anything else.
But whether it’s apportionment or boundaries, population base or gerrymandering, the solution is the same. These questions only arise because Australia and the US both rely on winner-take-all single-member districts. Move to proportional representation and the problem goes away.