General statements against Citizens United ruling
Alan Grayson, a Democrat, stated that it was "the worst Supreme Court decision since the Dred Scott case" and accused the court of opening the door to political bribery and corruption.
Republican presidential candidate and Senator John McCain, co-crafter of the 2002 Bipartisan Campaign Reform Act, said "there's going to be, over time, a backlash ... when you see the amounts of union and corporate money that's going to go into political campaigns". McCain was "disappointed by the decision of the Supreme Court and the lifting of the limits on corporate and union contributions" but not surprised by the decision, saying that "It was clear that Justice Roberts, Alito and Scalia, by their very skeptical and even sarcastic comments, were very much opposed to BCRA." He pointed out that "Justice Rehnquist and Justice O'Connor, who had taken a different position on this issue, both had significant political experience, while Justices Roberts, Alito and Scalia have none."
Senator Russ Feingold, Democrat of Wisconsin, and Co-author of the McCain-Feingold campaign finance reform, called the the Citizens United decision “a terrible mistake.”
Republican Senator Olympia Snowe opined that "Today's decision was a serious disservice to our country."
Jonathan Alter called it the "most serious threat to American democracy in a generation."