With regard to test used in determining whether statutory classification constitutes a denial of equal protection, “suspect classifications” are those based on race, alienage, national origin and sex. Related entries Bowers v. Hardwick Structural Error Gag Order Bostock v. Clayton County, Georgia Insurrection Act Impeachment of President Andrew Johnson Fitzpatrick v. Bitzer Marbury v. Madison Pennsylvania v. Union Gas Co. Parden v. Terminal Ry. of Alabama State Docks Dept.