NB: VotePlz is partially funded by YC president Sam Altman, although I am not sure if it is a part of YC (see interview w/ cofounders + Altman: https://www.buzzfeed.com/nitashatiku/voteplz-silicon-valley-...)
Non-profits don't need to earn money :)
Power and influence is ultimately traded as a commodity with the use of money. Other methods are not generalizable.
I don't think the goal here is to earn money, but rather to earn influence. So the question would be, what do they intend to use that influence for? What is the end goal?