There is no doubt that Super PACs, independent groups that are bankrolled by supporters of specific candidates, are playing a significant role in the 2012 primary campaign. In South Carolina, for example, Super PACs outspent the actual candidates on TV advertising - $8.9 million to $5.6 million. And, the largesse of casino magnate Sheldon Adelson (he and his wife have pumped at least $10 million into the pro-Gingrich Super PAC "Winning Our Future") has been a major factor in keeping Newt Gingrich's campaign alive.

Even so, don't blame the Citizens United ruling for the outsized influence of independent spending. Wealthy individuals have always been able to influence the process.

Colby College professor Anthony Corrado, a nationally recognized expert on campaign finance, tells me in an email that "most of the activity that has taken place in the presidential race so far could have been conducted under the campaign finance rules of 2008."

Or, even 2004.

Back in 2004 there was this little group called "Swift Boat Veterans for the Truth" that was bankrolled by wealthy Texas home builder Bob Perry to the tune of $4.4 million. Also that year, two guys who wanted to see a Democrat elected to the White House, George Soros and Peter Lewis, pumped more than $38 million of their own money into an independent organization called "Americans Coming Together."

Sheldon Adelson didn't need Citizens United ruling to allow him to put as much money as he wanted into an independent organization. In the olden days, pre-Citizens United, he would have formed a 527, like he did in 2008 when he put $30 million into a group called "Freedom's Watch."

What the Citizens United decision does allow that wasn't the case back in earlier elections is for these independent groups to accept unlimited corporate and labor union contributions and spend the funds on candidate advertising. Big corporations, wary of the negative PR that would come with donating to a political cause, are staying out.

The real difference between the Super PACs of 2012 and the Perry/Soros organizations of 2004, Corrado points out, is that the 2012 independent committees "started spending money much earlier." Moreover, Corrado notes, "they were established to serve as candidate-specific parallel campaign organizations to influence the outcome of the nomination, as opposed to waiting for the nominee to emerge and then engage in what was essentially a general election context."

In other words, outside money is having a big influence on this election. Just don't blame Citizens United. Yet.