Moline School District v. Quinn, 54 N.E.3d 825

Public Act 97-1161 (eff. June 1, 2013) amended the Illinois Property Tax Code to exempt leasehold interests and improvements on property owned by the Metropolitan Airport Authority of Rock Island County (MAA) when leased to a fixed base operator (FBO) providing aeronautical services to the public.
At enactment only one Illinois FBO met the statute’s terms at the Quad City International Airport (MAA): Elliott Aviation, which previously paid >$150,000/year in property taxes to Moline School District No. 40.
The legislative record shows the bill’s purpose was to induce Elliott Aviation to expand in Moline rather than in Des Moines, Iowa (where leaseholds were not taxed), thereby promoting local jobs and economic activity; attempts to extend the exemption to another airport were rejected in the legislature.
The School District sued for declaratory and injunctive relief alleging the Act violated multiple Illinois Constitutional provisions, principally the special legislation clause (Ill. Const. art. IV, § 13).
The trial court granted summary judgment for Elliott Aviation and dissolved a preliminary injunction; the appellate court reversed, holding the Act violated the special legislation clause. The Illinois Supreme Court affirmed the appellate court.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Public Act 97-1161 violates the Illinois Constitution’s special legislation clause (art. IV, § 13) by conferring a special tax exemption on a single FBO at the Quad City airport	The Act grants a special, arbitrary benefit to Elliott Aviation and similarly situated entities were denied the same treatment; no rational basis justifies singling out this FBO/airport	The classification is rationally related to legitimate state interests (encouraging in‑state expansion, job creation, economic development); Elliott is uniquely situated by proximity to Iowa and competitive tax differences	The Court held the Act violates art. IV, § 13: it discriminates in favor of a select group and the classification is arbitrary because no reasonable basis justifies restricting the exemption to this FBO at this airport
Whether other constitutional claims (due process, uniformity of taxation, art. IX § 6 exemptions) required resolution	School District raised additional constitutional challenges	Elliott argued primary resolution under special legislation clause was dispositive	The Court did not reach the other claims after finding the Act invalid under the special legislation clause; Justice Theis dissented and would have remanded to address other claims

Empress Casino Joliet Corp. v. Giannoulias, 231 Ill. 2d 62 (2008) (standard of review for constitutional challenges)
Pielet v. Pielet, 2012 IL 112064 (2012) (summary judgment in appellate review; de novo review)
Elementary School District 159 v. Schiller, 221 Ill. 2d 130 (2006) (special legislation clause; unique-situation exception)
Big Sky Excavating, Inc. v. Illinois Bell Telephone Co., 217 Ill. 2d 221 (2005) (two-part special legislation analysis: discrimination and arbitrariness)
Best v. Taylor Machine Works, 179 Ill. 2d 367 (1997) (history and purpose of special legislation prohibition)
Board of Education of Peoria School District No. 150 v. Peoria Federation of Support Staff, 2013 IL 114853 (2013) (definition of general vs. special law)
Crusius v. Illinois Gaming Board, 216 Ill. 2d 315 (2005) (rational-basis test for non-suspect classifications)
Chicago National League Ball Club, Inc. v. Thompson, 108 Ill. 2d 357 (1985) (legislature may address problems in incremental steps)
Allen v. Woodfield Chevrolet, Inc., 208 Ill. 2d 12 (2003) (arbitrary legislative classifications forbidden)