I would add some additional considerations to the points Brennan raises. Like most advocates of compulsory voting, Galston and Dionne contend that going to the polls is a duty we owe society, in order to make the political system work better. But this overlooks crucial ways in which it might actually make the system worse. On average, those who choose not to vote are even less well-informed about politics and public policy than current voters are. If they are forced to go to the polls, they will exacerbate the already severe problem of political ignorance. When relatively ignorant voters go to the polls, they aren’t doing the rest of society a favor. They are instead inflicting harm on us by making poor choices and incentivizing politicians to cater to their ignorance.
Admittedly, there are some situations where political ignorance can actually be beneficial, and ignorant voters might make better decisions than more knowledgeable ones. I discuss a few such scenarios in my book on political ignorance. But such cases are unusual exceptions. Most of the time, the most ignorant potential voters can better serve society by staying home on election day than by voting. As Brennan argues, there are many other ways for citizens to contribute to the public good. We should not assume that voting is the only, or even the best, way for us to do our civic duty.
Galston and Dionne suggest that mandatory voting will not exacerbate ignorance because voters’ “sense of civic duty makes them reluctant to cast uninformed ballots and inclines them to learn at least the basics about issues, parties and candidates.” But they offer no evidence to support this assertion, other than the fact that mandatory voting increases turnout in Australia, and relatively few voters spoil their ballots. Empirical evidence from countries that already have mandatory voting (many of which are hardly paragons of civic virtue) provides no proof that it increases political knowledge. Indeed, it seems unlikely that voters who choose to go to the polls only because they are forced to do so would feel a strong sense of civic duty that would lead them to make a serious effort to become well-informed. Because of their lesser interest in politics, the logic of rational voter ignorance is likely to apply to them with even greater force than most other voters.
Mandatory voting would be less dangerous if it could be combined with an effective strategy for increasing political knowledge. But doing so through education and other traditional means has turned out to be extremely difficult. Unconventional strategies, such as paying voters to become better-informed, also have serious pitfalls.
Galston and Dionne also argue that mandatory voting might lead to more moderate political outcomes by increasing the percentage of moderates and independents in the electorate. There is an obvious tension between that claim and the more standard left-wing argument for mandatory voting, which holds that it will move public policy to the left by increasing the percentage of low-income voters. Most studies suggest that mandatory voting would have only a modest effect on electoral outcomes, and that its main ideological impact is to increase voter support for xenophobic and “big government” versions of conservative populism. It is no accident that Donald Trump is a major beneficiary of political ignorance. He and others like him could well also benefit from mandatory voting.
But even if Galston and Dionne are right to believe that mandatory voting will promote moderation, it is not clear that this is a good thing. There is no reason to assume that moderate policies are necessarily better than more extreme ones. Sometimes, moderation in the pursuit of justice is no virtue, and extremism in the defense of liberty (and other important values) is no vice. Historically, there have been many situations where extreme views turned out to be more valid than moderate ones. For most of human history, gender quality and religious toleration were extreme views. Until the 1950s, the same could be said for full racial equality. As recently as twenty years ago, supporters of same-sex marriage were relatively isolated extremists. I am not suggesting that extremism is always good and moderation always bad, merely that whether a view is moderate or extreme relative to the current distribution of public opinion says little about its correctness.
I certainly do not claim that mandatory voting would be a complete catastrophe. I believe it would make the political system only modestly worse than it already is. But, as Brennan explains, the coercion involved in mandatory voting is itself a harm, one that at the very least requires a substantial societal benefit to justify. Galston, Dionne, and other defenders of mandatory voting have failed to meet that burden of proof.