Make voting mandatory for all citizens. Organize citizens into Voter Issue Alliances around specific issues of particular importance to them, their families, and their future. Trade the votes of an entire VIA for the support of a candidate to blunt the need for money to win elections.
Why is this important?
Most of the money for political campaigns buys advertising to influence how a person votes. If voters have already made up their minds how they will vote, the need for big money is greatly reduced.