PG's post below reminds us that many states still have their obscenity/disorderly conduct statutes in the books. However, while I'm not familiar with Chaplinsky, I am familiar with Cohen v. California, 403 U.S. 15 (1971).
On April 26, 1968, the defendant was observed in the Los Angeles County Courthouse in the corridor outside of division 20 of the municipal court wearing a jacket bearing the words 'Fuck the Draft' which were plainly visible. There were women and children present in the corridor. The defendant was arrested.
Cohen was tried under a statute applicable throughout the entire State. Any attempt to support this conviction on the ground that the statute seeks to preserve an appropriately decorous atmosphere in the courthouse where Cohen was arrested must fail in the absence of any language in the statute that would have put appellant on notice that certain kinds of otherwise permissible speech or conduct would nevertheless, under California law, not be tolerated in certain places.
In the second place, as it comes to us, this case cannot be said to fall within those relatively few categories of  instances where prior decisions have established the power of government to deal more comprehensively with certain forms of individual expression simply upon a showing that such a form was employed. This is not, for example, an obscenity case. Whatever else may be necessary to give rise to the States' broader power to prohibit obscene expression, such expression must be, in some significant way, erotic. It cannot plausibly be maintained that this vulgar allusion to the Selective Service System would conjure up such psychic stimulation in anyone likely to be confronted with Cohen's crudely defaced jacket.
While the four-letter word displayed by Cohen in relation to the draft is not uncommonly employed in a personally provocative fashion, in this instance it was clearly not directed to the person of the hearer. [internal marks and citations omitted].
Of course Cal. Penal Code Sec. 445 remains in the books exactly as it was written at the time. I'd take the ACLU position on this one...or just pay the fucking fine.