[Question] What are the charities that promote systemic political change?

I really like the idea behind approval voting advocacy as done by The Center for Election Science (https://​​electionscience.org/​​approval-voting-faqs/​​). I think it could have more impact to change how our political system works, not just individual politicians or movements (however there might be an argument that individual politician or movements could effect systemic change).

Are there other charities that are working on this kind of thing besides The Center for Election Science? I’d like to consider donating to them.

If there is some way to find this information out by searching the forum for specific keywords, or referencing some list for effective charities, that I could’ve done instead of asking this question here, please let me know as well for the future.