I may be wrong, but my impression is that the Gedolim consider it important/a Mitzvah to vote. I think that part of the reason for this may be that if the candidates see that a lot of Frum Jews vote, they are more likely to take Frum people’s needs and Israel into consideration. This would apply even if there is no one to vote for.
I also have heard that someone (maybe Rav Avigdor Miller) said that one should vote out of hakaras hatov to the US.
There are probably others here who know more about this me and can bring more accurate quotes on the topic.