The County sought to rely on its spending power to validate its ordinance. Unfortunately, they ran into the Judge Posner buzz-saw. First, he looked behind the holding in Wisconsin Dept. of Industry, Labor & Human Relations v. Gould, Inc., 475 U.S. 282, 290-91 (1986), for this key principle: the spending power may not be used as a pretext for regulating labor relations. Having established this principle, Judge Posner then systematically dismantles the one argument offered by the County in defense of its ordinance -- the need to protect the county against work stoppages.
In the end he has no problem reaching this conclusion:
On the contrary, we have seen that labor-peace agreements might well increase the frequency of service interruptions. The claim that the County is requiring labor peace agreements in order to further its interest as a buyer of services cannot withstand scrutiny. On this record, it is a pretext to regulate the labor relations of companies that happen, perhaps quite incidentally, to do some County work.The pre-emption argument was supported by an amicus brief filed by the NLRB, authorized by a 3-2 vote of the Board.
And a huge thank you to Mike Cernovich at Crime and Federalism for his instructions on properly linking to 7th Circuit opinions. Hopefully for the benefit of future readers, I got it right.