The United States Supreme Court has held that the Texas public school financing system, based on revenue raised by an ad valorem tax on property within a school district and resulting in substantial disparities in per-pupil expenditures between districts, did not violate the equal protection clause.
San Antonio Independent School District v. Rodriguez, 411 U.S. 1 (1973).
David L. Schwartz,
Constitutional Law - Equal Protection - Validity of Texas Public School Financing System,
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol12/iss2/10