A few key points that emerge from a first reading of the Roberts opinion:

1.  The Standard of Review for Contribution Limitations

The Court decides not to address the question directly and so it leaves undisturbed, at least in formal terms, the different standards of review, one rigorous and one less so,  employed for "contributions" and "expenditures," respectively. At the same time, one might ask whether, in any practical application, the differences between these standards matter much at all. This is because the Court continues to insist on a very rigorous definition of the necessary government interest in regulation – actual quid pro quo corruption of candidates or its appearance – and it also rules out an expansive use of anti-circumvention theories, usually highly conceptual as in this case, as a means of satisfying the requirements that any regulation of speech be "closely drawn" to match the government's interest. There will be ample debate in the coming days about whether the Court has effectively adjusted the burden against the government in contribution cases without actually tampering with the standard of review.

Rick Hasen has joined others in arguing that, if in McCutcheon the Supreme Court were to strike down the aggregate limit on political contributions, the large individual donor would be able to amass undesirable influence by donating to joint fundraising committees organized by candidates and parties. The money distributed through those committees is governed by limits—$2600 per participating candidate, etc.—but when first given to the joint fundraising committee, the total donated might be massive, in the millions, and the parties and candidates who would divide it up later could be insidiously grateful to the donor.

If the aggregate limit is a means of enforcing the base limits and blocking circumvention, it raises the question: how effective does an anti-circumvention measure have to be to prevail in a test of the provision’s constitutionality? In the case of the aggregate limit, the inquiry leads quickly to a consideration of a new fact of campaign finance—the super PACs.

Norm Ornstein predicts trouble if the Court in McCutcheon strikes down the aggregate contribution limits—the trouble of increased corruption. If You Think Citizens United Was Bad, Wait for This Supreme Court Case, The Atlantic (September 26, 2013). Brad Smith disagrees and argues that experience shows there is nothing to fear. The Next Battle in the Fight for Free Speech, Wall Street Journal (September 29, 2013). Two knowledgeable analysts come to these very different conclusions; the reason, it appears, is that they are not using the same doctrinal yardstick for measuring the potential for corruption.

Campaign finance jurisprudence is caught in the crosscurrents of formal doctrine and less clearly articulated judgments about the interests it is crafted to serve. One such judgment has to do with the “little guy”: the pamphleteer or small-scale political enterprise that raises and spends money to influence elections but whose activities have little or no corrupt potential and should not come within the regulatory grasp of the state. The Court has gone to considerable and inventive lengths to spare the little guy the dead weight of the rulebook, See, e.g. McIntyre v. Ohio Elections Comm’n, 514 U.S. 334 (1995) and FEC v. Massachusetts Citizens for Life, 479 U.S. 238 (1986) and it may have occasion in the near future to do more of the same. Because the doctrine is only roughly fitted to the purpose, the protection of the “little guy” has served the “big guys” well; an approach cobbled together on the fly for the smaller, more local enterprise has shielded the major political spenders.

Replying to a posting here, David Gans has responded with a confident defense of the brief he co-authored on behalf of Larry Lessig in the McCutcheon case. On the question of whether the aggregate limit is a contribution or expenditure limit, he has no doubt: it is an “easy” one, he writes. But how easy is it?