Australia has compulsory voting. Which is different from some parts of the US, where voter turnout is a major focus.
If you don’t make voting compulsory, then apparently you can end up with fascinating (although slightly bizarre) examples like the ‘voting violation’ notices sent by the Cruz campaign in Iowa.
Image from The New Yorker.
There’s some reasonable social science behind this. I can’t remember if I read it in Victory Lab or somewhere else, but my recollection of the theory is that individuals are more likely to vote when there’s a sense of social pressure. The emphasis for campaigns is to turn out voters
It’s hard to say if this is something that works once before it fades, or if it becomes an ingrained part of campaigning. Apparently it’s been done before in general elections. Either way, I think it’s fascinating.