President clinton, on the fortieth anniversary of the events in arkansas surrounding the "little rock nine," stated that "when the constitutional rights of our citizens are threatened, the national government must guarantee them." this principle was the basis for using federal authority in:

This principle was the basis for using federal authority in 1957 when President Dwight D. Eisenhower enforced federal court-ordered desegregation at Central High School in Little Rock, Arkansas.  Then governor Orval Faubus defied the court order and called out the Arkansas National Guard to prevent the students from entering the school. One thousand paratroopers were sent by the federal government to protect nine black students and escort them into the school.