Paul Krugman waxes nostalgic for the Nixon era, not because he likes Nixon, but because back in those days "moderate" Republicans and Democrats could come together to pass pretty much any piece of legislation that a liberal might want. The piece would be unremarkable if not for this line: "our corporate-cash-dominated system is a relatively recent creation, dating mainly from the late 1970s."
Let's leave aside the blithe assumption that if things aren't developing as Krugman would like, it must be that evil corporations are to blame. Surely it can't be that le Peuple, repositories of all that is virtuous, are opposed to Nancy Pelosi's health care proposals. Let's assume, for the sake of argument, that he is correct. Large corporations are not new to the United States, nor are campaign donations. Shouldn't the fact that this "corporate-cash-dominated system" has allegedly arisen in the environment created by the Federal Election Campaign Act and, more recently, McCain-Feingold make us a just a tiny bit skeptical about campaign finance reform? In this context, this 1995 study by Brad Smith seems more relevant than ever.