For a non-profit donation, I don’t see the need for disclosure. It’s an opinion, for what it’s worth, and only that. A legislator that may vote differently than his beliefs, depending on their constituents POV, may want to personally donate to a cause but actually vote the way of his constituents. This would, at least, give privacy to those that want it. Personally I don’t want my charity/non-profit donations public and too many things are “too public” sometimes.