The most basic explanation of the court's logic boils down to two conclusions. First, the limits on raising and spending money to support or oppose candidates for federal office are unconstitutional when the spending is not coordinated with the candidate's campaign. (Citizens United did not directly bring about the creation of so-called "Super PACs," it was the Speechnow.org v FEC decision three months later that said that organizations formed for the purposes of only making independent expenditures could not be limited in how much they raise and spend)Secondly (and much less talked about in coverage of Citizens United), it is much easier in the 21st century to provide quick, transparent disclosure of the sources of funds spent on political activities, so there is no reason to worry about secret influence. Of course, both of these conclusions have shown to be quite faulty in practice. On the first, groups that are not coordinating legally with the candidate are nonetheless able to coordinate in myriad ways that most people outside of the FEC would consider "coordination." For example, Restore Our Future and American Crossroads are super PACs supporting (explicitly and tacitly) Mitt Romney. Neither is not allowed to "coordinate" it's expenditures with the Romeny Campaign, yet they are deeply linked to one another in many ways. Most of the top donors to the groups have also maxed out to the Romney campaign. The president of Restore Our Future (Carl Forti) is also one of the founding memebers of American Crossroads, and one of the other founding members of American Crossroads (Ed Gillespie) just became a campaign adviser to the Romney campaign. The people in all three camps have deep personal and professional ties to one another (which they are allowed maintain despite restrictions on coordination). It is pretty hard to believe that the money spent by either ROF or AC is not in some way done with a close understanding of what the campaign would like them to spend money on. On the question of disclosure, let's take AC's sister organization Crossroads GPS, a 501(c)(4) group. GPS spent nearly $20 million in the 2010 midterms, but it isn't required to disclose any of the donors who made that spending possible. In fact, just last week, they filed their first Form 990 with the IRS, covering the 2010 period during which they made their political expenditures. Even with that disclosure, they did not have to say who gave them the money. In fact, GPS provided more disclosure than they were required to provide to the public, by way of a partially-filled schedule B -- which is always filed with the IRS but not made available to the public. The schedule B lists the donors and amounts given, and GPS provided the amounts given, but not the donors who provided the funds. A number of groups that spent more than $1 million in the 2010 midterms have yet to file a 990 with the IRS, so you can see that there are serious questions about the logic of the Supreme Court's view that disclosure would be timely.