Why? Via freedom of association we all can (and do!) pool our money very well, and we have more money altogether than the Soroses and Koches of the world.
This is becoming an increasingly serious problem, that contributions from the general public don't outspend rich people who are keen to push an idea.
http://www.harrowell.org.uk/blog/2017/11/19/the-theory-of-th...
(and http://www.harrowell.org.uk/blog/2018/01/26/pro-market-pro-b... )