Assuming
arguendo that the “secondary effects” doctrine extends to cases involving the prohibition of political signs on private property,
Ladue fails at sufficiently supporting its secondary-effects argument. Specifically, Ladue has not shown that the prohibited signs cause more aesthetic, safety, and property value problems than the permitted signs. Stated in other words, the prohibited signs are no more associated with the particular “secondary effects” than many of the permitted signs.
Compare Renton, 475 U.S. at 51–53, 106 S.Ct. at 931–32 (ordinance was aimed at the particular secondary effects that surround theaters featuring sexually explicit films). Ladue has “singled out” certain categories of signs for discriminatory treatment. The fact that the ordinance's differential treatment does not correlate with Ladue's interest in eliminating the secondary effects undermines Ladue's commitment to its secondary-effects justification and supports the contention that the ordinance is aimed at the content of the signs.
Compare id. (concluding that Renton had not “singled out” adult theaters for discriminatory treatment and that there was no evidence of under-inclusiveness). In short, the ordinance's sign exceptions, many of which cause the same secondary effects as the prohibited signs, renders the secondary effects doctrine inapposite to this case.