ad property may not be burdened for local
improvements upon a basis so wholly different from that used for
ascertaining the contribution demanded of individual owners as
necessarily to produce manifest inequality.[1099] A special highway
assessment against railroads based on real property, rolling stock and
other personal property is unjustly discriminatory when other
assessments for the same improvement are based on real property
alone.[1100] A law requiring the franchise of a railroad to be
considered in valuing its property for apportionment of a special
assessment, is not invalid where the franchises were not added as a
separate personal property value to the assessment of the real
property.[1101] In taxing railroads within a levee district on a mileage
basis, it is not necessarily arbitrary to fix a lower rate per mile for
those having less than 25 miles of main line within the district than
for those having more.[1102]

POLICE POWER

Classification

Justice Holmes once called the equal protection clause the "usual last
refuge of constitutional arguments."[1103] When State action is attacked
under the due process clause, the assailant usually charges also that he
is denied the equal protection of the laws. Except where discrimination
on the basis of race or nationality is shown, few police regulations
have been found unconstitutional on this ground.[1104] The Court has
condemned a statute which forbade stock insurance companies to act
through agents who were their salaried employees, but permitted mutual
companies to operate in this manner.[1105] A law which required private
motor vehicle carriers to obtain certificates of convenience and
necessity and to furnish security for the protection of the public was
held invalid by reason of the exemption of carriers of fish, farm and
dairy products.[1106] Discrimination among milk dealers without well
advertised trade names, giving those who entered business before a
specified date the benefit of a price differential denied to those who
commenced operations thereafter, is arbitrary and unlawful.[1107] A
statute providing for the sterilization of defectives in State
institutions was sustained;[1108] but a similar act applicable to triple
offenders was held void.[1109]

Administrative Discretion

A municipal ordinance which vests in supervisory authorities a naked and
arbitrary power to grant or withhold consent to the operation of
laundries in wooden buildings