Apparently 20% of 3rd candidate (R) did not mark up anyone as ranked choice, presumably some because they did not like Palin, and some because they did not get how this works.
Also, were the other R finished second, he would have been more likely to beat the D due to less empty protest votes.
Australians point out that their system is slightly different:
– you have to have a 2nd choice. Not sure this will be popular in US where you don’t force people to vote even for the first choice!
– only one candidate per party is allowed into the finals. This will help for some time, until parties subdivide.
My suggestion: to use candidate agreements instead of voter rankings, the way Israelis divide partial knesset seats. That is, candidate themselves decide who is most similar to them and gives them the votes he “earned”.