Prior to incorporation, each state decided.
That is true, but incomplete. With incorporation, each State still decides. Are you saying otherwise?
Of course.
Six years after Gitlow, the Court anchored this view, stating in Near v. Minnesota that "It is no longer open to doubt that the liberty of the press and of speech is within the liberty safeguarded by the due process clause of the 14th Amendment from invasion by state action."
-- Near v. Minnesota, 283 U.S. 697, 707 (1931)