At the highest level of generality is Ronald Dworkin's article on the Citizen's United decision in the New York Review of Books earlier this year. Dworkin is one of the world's foremost political and legal philosophers and in his piece (entitled 'The Decision That Threatens Democracy') he lays out both the theoretical issues around the right to free speech and the legal precedents for restricting that right to individuals, particularly in election campaigns. Its a long article, but worth checking out - it also includes a ringing endorsement fair elections legislation and the public financing of elections.
More specifics on the nuts and bolts of electoral reform comes from the Brennan Center for Justice's Memorandum on the Constitutionality of the Fair Elections Now Act. This is a detailed look at various judicial decisions and their implications for the Fair Elections Now Act. It concludes:
'The public financing system for congressional elections created by Fair Elections was carefully structured to maximize its ability to survive judicial scrutiny. Like all public financing systems, it enhances First Amendment values and does so while providing access to public funding to candidates of all stripes. For these reasons, the Brennan Center urges Congress to move quickly to pass Fair Elections so that congressional candidates can rely on their constituencies rather than on well-funded special interests for their political survival.'
Last but not least is a great blog post from Timothy Egan at the New York Times that gives a great analysis of the practical impact of the Citizen's United decision - the huge increase in personal attack adds by often unnamed always unaccountable private interests. He ends ominously, noting that the recently unshackled corporate interests will have developed their campaign operations even further by the presidential election in 2012, in which citizens can expect their electoral process to be even more effectively hijacked by a glut of corporate money.