ployers post an election notice three days before a representation election would be subject to challenge on that ground. See 29 CFR 103.20; see also Pannier Corp., Graphics Div. v. NLBB, 120 F.3d 603, 606-07 (6th Cir. 1997) (rejecting an as-applied challenge to § 103.20). Furthermore, under American Hospital Association, the