There's a whole amendment to the Constitution devoted to protecting it.
Actually, that is not true. The piece that has been misconstrued as protecting journalism** is only part of the First Amendment and is does not protect the "press" as we use the term today (to refer to the news media). When the First Amendment says "Congress shall make no law...abridging the freedom of speech, or of the press,..." it very intentionally links the right to say what you want to the right to publish what you want. The "freedom of the press" is not a right for journalists, but a right for every citizen to publish, if they have the means, whatever they wish (with the edge cases of slander and libel, although even there the original understanding was that the person slandered or libeled could not prevent you from publishing, they could merely receive punitive recompense if they could prove that it was slander or libel).
**the misconstrued part is that it is ABOUT journalism, not that it protects it. It does protect journalism, but only as a side-effect of protecting everyone's right to publish.