I may underestimate dumb, at least in the sense that many people obviously aren't good at cost-benefit analyses, but vote rigging isn't easy, either. We're far from the days where paper ballots can be stuffed or destroyed willy nilly. Places have electronic voting, or paper voting with electronic counters. So even if you're going to ballot stuff, which may be easy, ballot nullifying still is difficult (which you're supposing in this case); a local precinct volunteer can't just erase the counts by pressing the delete key. To do this would take a more coordinated and sophisticated effort, and I just don't see anyone putting in the time and taking the risk for no gain whatsoever. On your other point I agree that we need a national voting system, with rules, regulations and uniformity. If that were the case, we wouldn't need section 5 of the voting rights act, which the Court is going to nullify in the coming term (and I'll bet that at any odds).