The opinion will be released tomorrow morning. Tom Goldstein predicts that Justice Alito is likely writing the opinion. In my analysis of the oral argument, here is what I wrote about Justice Alito’s views at that point:

If we count Scalia, Thomas, and Kennedy as up to three votes to strike down the increased contribution limits for candidates facing self-financed opponents, the swing votes will likely be (as they were in the other two campaign finance cases of the Roberts Court, Randall v. Sorrell and WRTL II) Justice Alito and Chief Justice Roberts. (I assume Justices Breyer, Stevens, Souter, and Ginsburg would all vote to uphold the increased contribution limits.) Though these two Justices asked questions of both sides, both of them seemed attracted to the argument that the increased contribution limit provision is constitutional, because it provides more speech, not less speech. And rather than look for a justification an in equality argument—leveling the playing field—these Justices suggested that the law could be justified because it removes some of the first Amendment burdens on candidates by raising contribution limits. The problem with this line of reasoning, as these Justices also suggested, is that it does so for only one candidate, and not both candidates. So one outcome is upholding the provision; a second outcome is holding that Congress could permissibly increase the contribution limits, but such limits would be increased for the self-financed candidates as well.

Of course, things could have changed since oral argument.