Expert Answer
The primary purpose of 14th amendment was to validate the equality provisions contained in Civil Rights act of 1866 which guaranteed that all citizens have equal rights.
14th amendment has been used many times to decide important cases. In Brown Vs Board of Education ( 1954), the court has disallowed racial segregation and also the basis for dsicrimination in many similar cases. In Bolling vs Sharpe( 1954), the Supreme Court has informed that equal protection from law is also available against federal government. This was earlier available against State and municipal government only. In Plessy Vs Ferguson case(1896), the Supreme court clarified that racial segregation can be done but the civil rights cannot be violated. Hence, it asked a railroad company to provide separate coaches for coloured people.
Three Test cases where the court have used are:
Strict Scrutiny: Suspect classifications: Race, origin, religion , lineage ( Government has to show a compelling reason for discrimination)
Middle tier scrutiny: gender and illegitimacy ( Government only has to show that discrimation serves a compelling state interest)
Minimum Scrutiny: cases where government only has to show rational for scrutiny. For examples, cases where mentally retarded people may be at a disadvantage.