Money cannot be considered a form of symbolic expression the same way burning a flag is. Money only magnifies a certain idea, by giving it a greater platform. It is not a constitutive part of speech, or speech in itself. If someone burns a flag in political protest the point she’s making does not become more powerful or popular by burning additional flags, nor does her influence become directly proportional to the amount of flags she burns. The symbolic gesture of a donation and the endorsement that comes with it does not also require the right to spend unlimited sums of money to express one’s support.