With regard to the equal protection clause of the Fourteenth Amendment, in Plessy v. Ferguson (1896), 163 U.S. 537, 16 S.Ct. 1138, 41 L.Ed. 256, the U.S. Supreme Court declared that state laws requiring segregation of blacks and whites in schools (and ultimately in other areas) were not unconstitutional. The theory was that the mere separation of the racial groups did not constitute discrimination against either race and that separate but equal facilities were permissible. However, in Brown v. Board of Education (1954), 374 U.S. 483, 74 S.Ct. 686, 98 L.Ed. 873, the same court held that the separate but equal doctrine held constitutional in 1896 was unconstitutional in school segregation cases. The reasoning was that it was a violation of the Fourteenth Amendment to have separate but equal facilities.

Explain how the U.S. Supreme Court can decide in 1896 that separate but equal facilities are constitutional and then reverse itself in 1954. Is this an example of the bedrock principle or the living constitution principle?