I come from a country where the rigging of election is very common among top politicians, and am sure we all know how important voting is when it comes to the issue of making sure there is fair representation and equal voice in the process of decision making.
This issue of potential rigging and lack of transparency has gone a long way to discourage a lot of people from voting at all since they were of the belief that their votes doesn't count.
I think blockchain will be very useful in this area because it will help promote transparency, address security issues, which in turn makes rigging impossible and bring fairness to voting and decision making.
I think the registration and eligibility of voters can be done manually. After confirming that a voter is eligible, the voter can then be assigned a private key which will alllow them to be able to vote only once. With this, I think we should have a free and fair election.