Yesterday, the indispensable Supreme Court blog ran a discussion on what we know at this stage about how much the Citizen's United decision is affecting campaign financing.  Because I have a somewhat different view on this question than Rick Hasen (see this Slate piece), I will re-post my contribution here:

There is a tendency right now to attribute to Citizens United (CU) virtually all newly emerging forms of financing elections, and the increasingly large amounts, that arose in the 2010 election cycle and that look to play an even more central role in the 2012 elections. But this tendency can reflect a complacent sensibility among critics of Citizens United that the case is the source of all evil in campaign financing, or the desire of journalists and others to craft dramatic narratives that elevate single moments into uniquely transformative events. The truth is more complicated, for at least two reasons.

First, the most significant innovation – the rise of so-called Super Pacs, which can solicit unlimited contributions for purposes of independent electioneering – probably would have happened without CU. The organizational entrepreneurs that pioneered the Super Pac form, SpeechNow, came up with this idea in 2007 and pursued this strategy long before CU. It is really Buckley v. Valeo, from 1976, not CU, that establishes that Congress cannot regulate independent electioneering spending (other than through disclosure requirements). On this issue, CU did little more than confirm what Buckley had already established. In virtually every election cycle in our highly competitive, polarized era, innovators have created new organizational forms or exploited existing ones (527 organizations, 501(c)(4) entities). Super Pacs should be understood as the most recent stage in this cycle, not as some radical new structure made possible only by CU. CU does affect whether corporate and union general treasuries can contribute to these Super Pacs; but Super Pacs, funded with unlimited contributions by wealthy individuals and various other entities would exist without CU, once aggressive innovators figured out Super Pacs would best serve their interests.

This leads to the second point: we simply do not know at this point how much corporate money is or is not flowing to Super Pacs or other campaign-finance entities. Large, publicly traded corporations might be less likely to get involved in election financing than many people tend to assume – particularly if that involvement must be publicly disclosed. A recent, authoritative study concludes that 60% of companies in the S & P 100 Index have already responded to CU by prohibiting spending corporate money on politics or disclosing their direct political spending and adopting Board oversight. Such spending risks alienating potential customers; it can trigger shareholder backlash; and, frankly, corporations probably are able to attain influence more efficiently through spending their money on lobbying on specific issues, rather than generally trying to influence election outcomes. Privately-held corporations, or those dominated by a single shareholder, are probably more likely to engage in election spending. Moreover, we are still in the middle of working out what kind of public, regulatory regime for disclosure will end up being required; the SEC, for example, has been petitioned to adopt such requirements. Until we know what kind of disclosure of direct and indirect corporate spending will be required, we won’t know how active corporations will end up being. And because we don’t have such a regime in place yet, we are left with a lot of speculation, but little actual information, about how much corporate spending is actually taking place.