Due to how federation works, downvotes are actually somewhat public because instance owners can query them in lemmy database, though instance owners probably won’t tell you if you ask due to privacy reason. If you’re interested in something like this, you can run your own instance.
I may not agree with the devs political view, but I think their work developing lemmy is excellent and made me subscribe to monthly donation on opencollective. Lemmy is an open source project where the devs have absolutely no say over how the software being used, as evidenced by so many lemmy instances defederating from lemmygrad and lemmy.ml. Their political belief won’t affect other instance.