In analyzing two races on Oahu, I noted that for those races that had competition - more down ballot and not high profile like the Mayor's or Congressional races, there was in my view more participation by voters. Another factor that I saw was, in specific races I am informed on, the more effort was given to Get Out the Vote by the campaign did result in more voters coming out to vote in that race. Considering that in the past the parties did the GOTV way more than the candidates, this was an interesting development. 

Finally, noting two races that had only one candidate in them, the blank votes for them were quite high. A question that did come up is whether that blank vote was a protest against that person. My opinion, it was more a local attitude: "Eh, the guy going win anyway, so why I vote?" This goes right back to whether the sole candidates did a GOTV. the ones that did got better turnout and less blanks than the ones that didn't.