You can rationally be displeased what you expect the outcome of the case to be (e.g. increased ability for corporate financing of election campaigns), but I don't think there's a coherent defense of the sections of BCRA that the court struck down.
ETA: The government argued that BCRA would allow them to ban, for example, a 500 page book that contained a single sentence endorsing a candidate (http://reason.com/archives/2010/06/29/will-elena-kagan-allow...). If you think SOPA is heavy-handed, just think what BCRA could have led to.
Of course, I'd say the people they serve are are quite happy to ignore them when it's convenient for the court aristocracy, but I can't see them as guilty of any obvious inconsistencies.
I see a big distinction between putting out an original movie that mentions a candidate (the issue in Citizens United) and building a website to distribute other people's movies (the issue in SOPA).
Edit to clarify: distribute other people's movies without their permission.