Fix campaign finance like this:
1) Only individuals eligible to vote may make campaign contributions, in any amount. Since organizations can’t vote, it seems clear the founders did not intend “organizational interests” to influence campaigns. No contributions from foreign sources, period.
2) Names and amounts donated would be immediately disclosed on campaign websites. I don’t want to hear about privacy here. You can’t, on the one hand, demand the right to make contributions as “political speech” and, on the other, demand to keep such “speech” secret. It can’t be speech if you don’t want it heard. Funds would be held in escrow until the eligibility of the contributor is verified. No more “oops I used your illegal contribution to get my campaign rolling, but I’ll give it back since it was discovered.”
3) Outsize contributions would be acceptable as prima facie evidence of bribery if actions taken by the candidate, once elected, specifically benefit the donor. Officials would be prosecutable. In any case, we would know clearly who was in the pocket of whom. Political officers would be presumed guilty until they make a case for innocence.
4) So called “issue ads” by non-campaign organizations would be subject to the same disclosure requirements. Only voting individuals may contribute, full disclosure of names and amounts.
There is no way to control it in monetary terms.
I think the better way is election changes.
1. The current House of Representatives should have many more people than what they do. For a nation of 300 million, the House should have in the neighborhood of 3000 members.
Much smaller congressional districts make KNOWING the people you vote for a much more likely result.
2. Repeal the 17th amendment, and then put Senatorial selection back in the hands of state legislatures.
3. Return the presidential election to the Electoral College, and with the larger House of 3000 members, the battle in each district will be over the ELECTOR that that congressional district chooses. The College will then choose the president with the majority of EC votes. In other words, it will be a republic and not a democracy. We know that majority rule doesn’t work.
4. Amend the constitution to require term limits for all federal legislators, senators, judges, presidents, and the upper two levels of civil type service.