Last night, a federal jury in Chicago convicted Illinois governor Rod Blagojevich on just one of 24 counts of political corruption. On the rest of the counts, the jury was hopelessly deadlocked.

Scott Turow, the bestselling novelist who started his career as a US Attorney prosecuting political corruption cases in Chicago, writes in the New York Times that whatever the fuzziness of fact in the Blagojevich case, what is even fuzzier is the way our legal system deals with political corruption. The influence of big money is everywhere in our political process—and the Supreme Court’s decision in Citizens United opened the door for less showy, but equally problematic, versions of the corruption that Blagojevich is accused of.

Indeed, in Citizens United v. Federal Election Commission, the court decided that such organizations could spend as much as they wished at any time, assuming there was no direct coordination with the candidate. In doing so, the court overturned its own precedents and refused to distinguish the free speech rights of corporations and unions in any way from those of actual people.

The problem with this logic is that corporations have a legal duty not to spend money unless it is likely to improve profits. Unions, too, are expected to make only contributions that will benefit members. As a result, no idealistic patina of concern about good government or values-driven issues can burnish these payments.

The future of other campaign finance restrictions looks bleak. Thirty-four years ago, when the Supreme Court first declared in Buckley v. Valeo that the First Amendment protected election spending, it nonetheless approved contribution limits “to prevent … the appearance of corruption.” In Citizens United, the Roberts Court gave short shrift to any concern about appearances. Limits on direct contributions to candidates appear likely to be the next campaign safeguard to fall.

In any case, the bevy of ways in which donors can get around current spending laws, combined with the Supreme Court’s elastic approach to the First Amendment, have left our campaign finance system as little more than a form of legalized influence-buying. Only those as naive as Wanda Brandstetter or as crass and ham-handed as Rod Blagojevich find themselves subject to prosecution, while others wise enough to say less out loud find snug protection in the First Amendment, no matter how bald their desire to influence government actions.

We see daily examples of this sort of dynamic happening in elections—take the Florida governor’s race–where any causal relationships between campaign cash and policy decisions can never be fully sorted out. It’s a dangerous thing for democracy…and one, as Turow points out, we aren’t going to fix without a Constitutional amendment.