Was the Court Conned in Citizens United?

Bloomberg:
"What went wrong? The answer lies buried in the graveyard of election-law enforcement: the Federal Election Commission. In 2007, prior to Citizens United, the FEC issued a little-noticed 'interpretation of law' that narrowed the scope of the McCain- Feingold disclosure requirements. The law itself specifies that disclosure is required of 'all contributors' of $1,000 or more to groups running electioneering communications. The FEC interpretation changed that, requiring disclosure only of contributors who gave money 'for the purpose of furthering electioneering communications.' Of the commission’s six members, all three Democrats and one Republican voted for the change -- the result of a compromise that kept another Republican commissioner from achieving an even more extensive gutting of disclosure rules."