In the United States ex rel. Texas Portland Cement Company v. McCord case of 1913, the Supreme Court ruled on a dispute involving tax assessments and property valuations. The Texas Portland Cement Company challenged its assessed taxes, arguing that they were unfairly high because their property was overvalued by local authorities in Bexar County, Texas. They claimed this violated the Fourteenth Amendment's Equal Protection Clause as other similar properties were not valued or taxed at such rates. The court rejected these claims stating that there was no evidence to suggest intentional discrimination against the company by local officials nor any violation of equal protection rights under federal law since state laws allowed for differences in valuation methods among counties within a state. Furthermore, it held that minor discrepancies in taxation did not constitute an infringement upon constitutional rights unless there is clear proof of systematic discrimination.

In the dissenting opinion for the United States ex rel. Texas Portland Cement Company v. McCord case, it was argued that the majority's decision to uphold a tax on foreign corporations doing business in Texas contradicted previous rulings of the court and violated constitutional principles of equal protection under law. The dissent contended that there was no substantial difference between domestic and foreign corporations which would justify different treatment under taxation laws; both types of entities were engaged in commerce within state borders and should be subject to uniform regulations accordingly. Furthermore, they asserted that by imposing an additional burden on out-of-state companies, Texas effectively discriminated against interstate commerce - a practice prohibited by federal law as per prior Supreme Court interpretations.