Require politicians to recuse themselves from voting in conflict of interest.

Getting the dirty money out of politics is probably nearly impossible. A solution is to require politicians to recuse themselves from voting on legislation when they have a clear conflict of interest. The primary idea is to remove reward for large campaign contributions by making it illegal to vote on an issue affecting a donor. Thus, we could allow unlimited "free speech" contributions keeping the supreme court happy, but remove the quid pro quo that is driving the system. Joe corporation can give all the money they want, but receiving senator Bob will not be allowed to vote on issues relating to Joe corporation. Thus, the only reason for Joe to give to Bob is for true civic mindedness, not to gain business advantage.