The U.S. Supreme Court’s decision in Citizens United v. FEC was certainly a blockbuster. And if you followed the past week’s media coverage and listened to the pundits, the implications seem pretty clear: A wave of unlimited corporate cash is about to flood our political process, benefiting big business and Republicans, and making the 2010 election cycle even more difficult for Democrats and progressives than it already was. Right?

Not so fast. The consequences of changes in the campaign finance laws — both legislative and judicial — have proven notoriously difficult to predict. This landmark decision — important as it is — will be no exception. Although Citizens United will certainly alter the regulation of campaign spending in significant ways, it’s easy to overstate the extent to which it actually changed the rules and it’s hard to foresee the implications with any real confidence.