"So Kagan... is a successful scholar whose interests have extended beyond scholarship, to government service and to educational institution-building."

Eugene Volokh defends Kagan as a legal scholar.

The [First Amendment] articles attack difficult and important problems (Private Speech, Public Purpose, for instance, tries to come up with a broad theory to explain much of free speech law). They seriously but calmly criticize the arguments on both sides, and give both sides credit where credit is due. For instance, I particularly liked Kagan’s treatment of both the Scalia R.A.V. v. City of St. Paul majority and the Stevens concurrence, in her Changing Faces of First Amendment Neutrality article.

As importantly, the articles go behind glib generalizations and formalistic distinctions and deal with the actual reality on the ground, such as the actual likely effects of speech restrictions, and of First Amendment doctrine. (I’m a big believer in formalism in the sense of a preference for rules over standards; but I share many people’s disapproval of formalistic arguments in the fashioning of rules, when those arguments ignore real-world distinctions and effects, and obscure the important policy questions rather than revealing them.) This is legal scholarship as it should be, and as it too rarely is.

And what kind of free speech opinions can we expect Justice Kagan to write:

My guess is that the likeliest bet would be to say that a Justice Kagan would be roughly where Justice Ginsburg is — generally pretty speech-protective, but probably with some exceptions in those areas where the liberal Justices on the Court have taken a more speech-restrictive view, chiefly expensive speech related to campaigns and religious speech in generally available government subsidies.