The highest level of constitutional protection courts can apply in determining whether a law or governmental action violates equal protection guarantees in the Fifth and 14th Amendments. To meet strict scrutiny, a law must satisfy two requirements: It must serve a compelling state interest and it must be narrowly tailored to serve that interest.
For example, laws that affect fundamental rights, such as voting or the right to travel, or which treat people differently on account of race, national origin, or religion, are subject to this exacting test.
www.justicelearning.org, The United States Constitution, what it says, what it means, A Hip Pocket Guide (Oxford University Press)