In their book Campaign Finance and Political Polarization: When Purists Prevail, Raymond La Raja and Brian Schaffner argue regulations don’t keep money out of politics so much as redirect the channels through which money gets into politics. Slap limits on donations to political parties, and people begin giving to candidates. Slap them on candidates, and they give to super PACs. That means you can use the different regulations of different states to learn quite a bit about how different fund-raising rules change politics.
