The recent Harley-Davidson opinion from the Superior Court of California, County of San Diego is an alarming example of why it is important to apply the appropriate constitutional standard in state tax cases.  In a Commerce Clause challenge, where the taxpayer argued a California statute discriminated against interstate commerce, both the California Appellate Court and the trial court applied Equal Protection standards in their Commerce Clause analyses.  In doing so, the courts upheld an otherwise discriminatory tax scheme on the grounds that it furthered the state’s legitimate interests in generating revenue and ensuring income is fairly apportioned among the several states.  Such a holding effectively guts the protections offered under the dormant Commerce Clause and highlights the analytical differences between discrimination under the Commerce Clause and discrimination under the Equal Protection Clause.