The greatest aspiration non-centrist movements can seriously have in Australia is to exert a gravitational effect on the mainstream. We saw that in the late 1990s and early 2000s when John Howard’s government neutralized the One Nation party by adopting a handful of its policies. On the left, the Greens have siphoned off some of Labor’s support, but apparently hit a ceiling around 10 percent of the vote. Lately they have been adopting a more centrist posture.

None of this means Australian politics is impervious to shock. Like much of the West, we’re in our own anti-incumbent, anti-system cycle. But compulsory voting means this movement is more gradual: a slow-motion accumulation of developments rather than the rapid agitation of an energized minority storming the barricades. Major parties will have time to adjust, and if not, minor parties will have time to mature.

But to my Australian eyes, the strongest case for compulsory voting came in the final stages of the recent American presidential campaign, when the candidates became obsessed with turnout.

On the Democratic side, this meant that President Obama was typically surrounded by pop stars while racing between rallies for Hillary Clinton. For the Republicans, it devolved into a bizarrely anti-democratic spectacle: efforts by Republican state officials to suppress the minority vote; Mr. Trump’s exhorting his supporters to monitor selected communities for “voter fraud.” Such actions — especially suppression of the black vote — should be enough reason to mandate voting, consigning this sordid gaming to history.

This isn’t particularly revolutionary if you see voting not merely as a right, but as a civic obligation. That might sound un-American, but Americans already have many such obligations, including more onerous ones like paying taxes or jury duty.

Even the most persuasive argument — that compulsory voting violates free speech ideals that include the right to silence — misunderstands how compulsory voting works. Voters are not compelled to support a candidate or even to cast a valid ballot. They are obliged to turn up.

Leave your form blank if the options are so uninspiring. Draw pictures on it. Even this is useful: By tracking the growth of these “informal” votes we can gauge voter dissatisfaction.