One who is proud to withhold their support, allegiance, or commerce from a person, organization, cause, political party, or ideology with whom they are in disagreement with or indifferent towards.
Although a proud non-supporter may never sound off publicly or on social media about their dislike of something or someone, they will put their money where their mouth is. One who boycotts something or someone is a good example of a proud non-supporter. There are other proud non-supporters who are very vocal about who and what they will not support. One does not necessarily have to be against something to be a proud non-supporter. One need only be indifferent toward a person, organization, cause, political party, or ideology and be proud of their indifference.
I'm a proud non-supporter of the New World Order and their globalist agenda. I'm proud that I refuse to drink their Cool aid.