Amend the Constitution to state that all candidates for any political office can only accept campaign money from a US Citizen who is registered to vote in the jurisdiction of the office for which they are running, subject to a per citizen, per election, per candidate limit of 10% the Federal Poverty standard for a single person (presently the limit would be about $1,000). Also, any public advertisement that mentions a candidate by name must be entirely paid for by that candidate's official campaign fund.
This will:
Restore control of our government to the voting citizens, where the Founding Fathers intended it.
Stop corporations from giving politicians bribes/campaign money, since they can't vote
Scale the contribution limit with the economic fortunes of the poorest among us.