Richard Briffault and I (along with our co-counsel David Ettinger of Horvitz and Levy and Marty Lederman of Georgetown) have written this pro-bono amicus brief supporting the FEC and the congressional intervenors in the Wisconsin Right to Life case being heard by the Supreme Court on April 25.
Here is the introduction to the brief:

This case involves yet another attack on the 60-year old requirement that corporations use separate segregated funds (or PACs), rather than treasury funds, to spend money in connection with federal elections. The Court has repeatedly addressed the PAC requirement, and has sustained its constitutionality, most recently three Terms ago in McConnell v. FEC, 540 U.S. 93, 203-11 (2003). The Court has done so not because election-related speech is entitled to less constitutional protection than other forms of political speech, but because, in the context of the election of public officials, legislatures and the Court have repeatedly recognized compelling justifications for regulations that might not be present, or as compelling, in other settings.
At the same time, the Court has recognized that the Constitution sometimes requires the creation of as-applied exemptions from otherwise permissible campaign finance regulations. As-applied exemptions are appropriate, the Court has explained, when the burden on speech in a particular application significantly outweighs any effect the regulation may have in promoting electoral integrity and other compelling legislative objectives — especially where a particular application of the law does not raise any of the concerns justifying regulation. Thus, for example, in Buckley v. Valeo, 424 U.S. 1 (1976), and Brown v. Socialist Workers ’74 Campaign Comm., 459 U.S. 87 (1982), the Court created and applied an exemption from general — and constitutionally sound — campaign disclosure requirements for minor political parties that can demonstrate that disclosure of contributors’ names would have an unusually severe chilling effect on the parties’ and contributors’ First Amendment activities. To similar effect, in FEC v. Mass. Citizens for Life, 479 U.S. 238, 260-61 (1986) (MCFL), the Court held that the First Amendment requires an exemption for certain nonprofit corporations from a corporate PAC requirement similar to that at issue here, because applying the requirement to such nonprofit corporations would not further the government interests underlying the requirement.
The Court should adopt a similar approach to as-applied exemptions in this case. The regulation in question here is a 2002 enactment, section 203 of the Bipartisan Campaign Reform Act of 2002, which was aimed at ending widespread evasions of the corporate PAC requirement. This case presents the question whether and under what circumstances the Constitution requires another exemption to the PAC requirement for corporations, beyond the exemption recognized in MCFL and in BCRA itself in section 204. We respectfully submit that any as-applied exemption ought to build on the principles for identifying such exemptions that the Court developed in Buckley, Brown, and MCFL.
The district court below failed to follow the Court’s guidance in these cases. It did not even attempt to tailor its proposed as-applied exemption to those advertisements that are unlikely to implicate the compelling government interests underlying section 203. Congress found, and the Court has agreed, that broadcast ads that name federal candidates in the immediate pre-election period almost invariably have an impact on voters’ choices in the election. Yet the district court would exempt many of those ads from regulation. If upheld by the Court, the district court’s test would thwart Congress’s objectives and return us to the days immediately preceding BCRA, when corporations easily evaded the PAC requirement.
We believe that a more appropriate test would exempt only those communications not implicating the governmental interests underlying the corporate PAC requirement. We propose that a corporation should be entitled to an as-applied exemption from the PAC requirement for electioneering communications only when it proves that an identifiable type of communication is unlikely to have any appreciable effect on voters’ choices in the election. Following the approach Congress took in BCRA and the Court’s analysis in McConnell, whether the corporation is entitled to an as-applied exemption for an ad must be based on a consideration of the context as well as the content of a broadcast advertisement.
The Court’s task in setting the balance between the proper scope of election regulation of corporations and the protection of corporate speech is a difficult one. Both Congress and the Court struggled with it, and BCRA and McConnell have struck a workable and proper balance. Any as-applied exemptions should not subvert that balance.

UPDATE: Unsurprisingly, Bob Bauer is not convinced.