Weird cause I've got the FTC act right here. Says this:
(a) Declaration of unlawfulness; power to prohibit unfair practices; inapplicability to foreign trade
(1) Unfair methods of competition in or affecting commerce, and unfair or deceptive acts or practices in
or affecting commerce, are hereby declared unlawful.
And then later on it has this whole entire section where it lays out the process for how the FTC is supposed to make rules in regards to unfair or deceptive practices
Except as provided in subsection (h) of this section, the Commission may prescribe--
(A) interpretive rules and general statements of policy with respect to unfair or deceptive acts or
practices in or affecting commerce (within the meaning of section 45(a)(1) of this title), and
(B) rules which define with specificity acts or practices which are unfair or deceptive acts or practices
in or affecting commerce (within the meaning of section 45(a)(1) of this title)
And more sections about how they can enforce those rules on individual rule breakers.
Sure sounds like congress was trying to give the FTC the authority to make rules about unfair competition. Both general rules and with "specificity" apparently.