even if the new rule is understood to compel employer speech, Section 8(c) ‘““merely implements the First Amendment.” Brown, 554 U.S. at 67 (quoting NLEB v. Gissel Packing Co., 395 U.S. 575, 617 (1969)). Thus, if a First Amendment challenge to the rule must fail, so too must a challenge based on Section 8(c). Such was the h