If one Virginia voter does an expected 1/(3.5 million)*($7 trillion) = $2 million good by voting for candidate X, then there is another Virginia voter that does an expected $2 million of damage by voting for candidate Y. It seems that either

1. Roughly half of the population is misinformed about which alternative is objectively better. In that case, how do I justify a belief that I have a greater than 50% chance of being right, when everyone else has access to the same information?

2. There are real differences in values, and by my vote I direct the outcome towards my preference instead of the other Virginia voter's. In that case, sure I want to vote, but should we really call it altruism?