Having lived in a country with compulsory voting (Argentina), I find the notion charming but I can scarcely say it leads to more intelligent outcomes.
Having 70-80-90% participation with non-compulsory voting should be the goal of any self respecting democracy and politicians who reject measures to increase voter turnout should be viewed with extreme suspicion.
Not really: Voters can still choose to "not participate" (whether as protest or laziness) simply by casting a ballot that is functionally empty of choices.
If anything, the signal you're talking about becomes stronger, since a compulsory-voting system removes or reduces certain practical impediments which have nothing to do with deliberate protest.
The signals are different. I cast a blank vote to indicate my support for the process/election, but my lack of support for any of the candidates. I cast no vote to indicate my lack of support for the process itself.
Non-voters and blank/invalid voters are usually reported separately to give exactly these 2 signals.
The US has a long history of voter suppression, which is often supported by the remaining voters. There's a lot of court cases about it; states will fight hard to reduce the impact of the ""wrong kind"" of voters.
Total utter rubbish.
Australia has compulsory voting .. meaning 98% of people turn up or mail in a "vote" and have a barbeque on the day.
The "signal" you falsely claim to be missing is right there in the donkey votes and duds - anybody that objects to the candidates presented is free to draw a dick and balls on the ballot or pencil in a candidate of their choice .. and that signal is anonymous, counted and logged.
You are missing the point. It's not about objecting to candidates. It's two separate signals sent by on the one hand abstaining, and on the other hand filling out a blank votes.
Blank vote means "I think this is a legitimate election, I just don't like any of the candidates".
The distinction between these two signals is important enough that most democracies around the world preserve it by not having compulsory voting.
Australia has compulsory voting and retains this: the legal req is to show up and get your name marked off.
If you wish to communicate your dissatisfaction with the available candidates, then you then fill out your ballot with a giant penis and go on your merry way.
To play devil's advocate and to argue for compulsory voting for a moment, however: It is a potential antidote to the type of voter apathy by which a somewhat demoralized but popular party (e.g. Democrats in the last US election) put themselves out of power by not being as motivated as a smaller group.
So while knowing the width of the motivation gap is useful, a polity could also just compel everyone to vote and then ask if they would have done so if not compelled, to get that information. Which is worse: Inaccurate data about voters' excitement, or sudden and surprising political shifts because people were sure they didn't need to go out to vote because they assumed their party had the majority?
Without compulsory voting, only those with strong motivation will vote - and there is no guarantee that an outsized motivation on one extreme side of the spectrum will not drastically and surprisingly take over if most people felt safe staying home. Austria right now seems to be a good example.
Put simply, the effort to become a voter should be equal regardless of wealth. I like the idea of imposing the difficulty the minority poors have in getting an ID on the white better off. Can you imagine Musk having to make multiple in-person trips to the DMV and wait an hour each time he is there?
Better then to vote for yourself, vote blank, vote for whoever you would rather have in charge, or vote for the least bad.
Not voting can be dissent (I disagree with the process, I don't think it's fair etc) or simply apathy. But in either case it gives less legitimacy to whoever is elected. And that's important: if you don't think it's a fair election/process then you don't want to give the legitimacy.
If you get killed on the high ground, you’re still dead.
Why on earth would you prefer a signal of legitimacy over 70/80/90% vote participation? Get people engaged.
(It's far from the only reason states don't use compulsory voting, I should say. There are many reasons both to have compulsory voting, and many arguments against. But the fact I was trying to point to was that the vast majority of countries don't use mandatory voting - because, one must assume, they feel the cons outweigh the pros)
"There are many reasons both to have gerrymander and not have gerrymander. The USA has gerrymander, because, one must assume, the USA feels the pros outweigh the cons."
Countries don't make the laws. They delegate that job to politicians. It should come as no surprise that even for an obviously anti-democratic practice like gerrymander, politicians get away with adding laws that favour them personally over democracy.
As for the arguments on www.idea.int, they say the leading one is "the leading argument against compulsory voting is that it is not consistent with the freedom associated with democracy". It's a circular argument. You don't have complete freedom under democracy, and there is no definitive list of freedoms democracy does give you. It varies from country to country. In some countries you don't have the freedom to not vote. So the argument made is really: "the leading argument against compulsory voting is that it is not consistent with the freedom associated with definition of democracy I just made up".
The other argument they raise is "random votes". True, there are random votes - 7.3% according to them. But that 7.3% is swamped by the 40% of additional voters in the USA who vote if you had compulsory voting. Besides, I'm suspicious of that 7.3% figure. In Australia we measure these things as best we can, and the figure is 1% .. 2%. Informal votes are around 5%, which if you add them together does bring the total to 7%. A vote is counted as informal votes when it's impossible to determine the voters intentions. Some are deliberate protests, but it seems most are just mistakes. In any case, they aren't "random votes" and don't effect the outcome directly so the 7.3% figure is misleading.
I've never head an Australian (where we do have compulsory voting) make what www.idea.int says is the leading argument for compulsory voting, which is that "decisions made by democratically elected governments are more legitimate when higher". Again, since I've never seen a solid definition of "legitimately elected government", I suspect it also suffers from the "definition I just made up" problem. I fact I've never heard anyone make any of the arguments on www.idea.int's list.
What Australians do say is it makes detecting many types of voting fraud easier, because it becomes trivially easy to check people votes just once: count the votes. Because detecting voting fraud is easy, there are no stringent ID checks. You just turn up, no ID required, get your name crossed off the electoral roll, get your ballot paper and vote (or not). So it in compulsory effect makes it easier to cast a vote. It also makes voter disenfranchisement much harder for a pollie to pull off, because people start yelling loudly if they cop a fine because someone makes it near impossible. Surprise, surprise, disenfranchisement is common in the USA: https://en.wikipedia.org/wiki/Voter_suppression_in_the_Unite... It's not a thing in Australia.
Those are clear and obvious effects. A debatable one that I think is true is it pulls the vote toward the centre. The people pushing for extreme views always vote because they want things to change. Those that are happy with things as they are sometimes assume it will continue if they do nothing.
But the only punishment you get for not voting is at most a small fine and that you have to jump through some hoops to get on the register of voters again. But it seems to work in practice to get people to turn out.