large-scale democracy is going to get exponentially more expensive with time, or die altogether. The one rule in cyber-security you should all know is that total security is impossible. Is the software on your voting machines open source? Can you open it up and take a look at the time? Well here in the US at least the answer to both of those is no. Even if you could do both of those, you wouldn't have any ability to verify the hardware itself (and that applies to both voting machines and home computers). So basically everything would have to be done with paper ballets. That's a whole other story, and is far less efficient. To be able to verify votes correctly after the fact, who's vote it is specifically would have to be saved. That's typically seen as a bad thing, as people can be targeted for their votes.
so basically large scale democracy isn't gonna work out very well