While attempting to register to vote in Louisiana in the early 1950s, Lucius Barker was required to take a test about his understanding of the Constitution. The test, rarely administered to white residents, was designed to discourage black citizens from voting.
Dr. Barker, then a graduate student of political science, answered most of the questions with ease. When the registrar asked him to explain the due process clause of the 14th Amendment, which provides that no one should be deprived of "life, liberty, or property, without due process of law," Barker said he couldn't give an answer.
"You don't know?" the registrar asked.
"No, I don't know, and neither does the Supreme Court," Barker replied.
He then cited several cases in which the court interpreted the clause in different ways - and deliberately mentioned unrelated cases to satisfy his curiosity that the white registrar did not understand the questions he was asking.
Barker was ultimately successful in his effort to register.
After attending segregated schools in his home state of Louisiana, Barker became a leading scholar of the political implications of race, civil liberties and the judicial system. His students at Stanford included Sen. Cory Booker, D-N.J., and twin brothers Julin Castro, a former U.S. housing and urban development secretary, and Rep. Joaquin Castro, D-Texas.
Barker died June 21 at his home in Menlo Park, California, at age 92. The cause was complications from Alzheimer's disease, said his daughter Heidi Barker.
He was known for developing the idea of the Supreme Court as a "safety valve," resolving sensitive issues that the legislative branch could not.
In 1970, he and his older brother, political scientist Twylie Barker Jr., published the first edition of "Civil Liberties and the Constitution," which provided historical context and what Barker called "systemic perspective" for Supreme Court rulings on civil liberties cases.
In 1976, Baker published "Black Americans and the Political System," which offered a comprehensive view of black political experience through history.
After years of studying politics from afar, Barker took a more active role in 1984, when he supported the Rev. Jesse Jackson's failed presidential bid and served as a delegate to the Democratic National Convention.
He later participated in Jackson's 1988 campaign and in Barack Obama's successful run for the presidency in 2008.
Lucius Jefferson Barker was born June 11, 1928, in Franklinton, La. Both of his parents were teachers, and his father became a principal in the then-segregated schools of Louisiana.
He received master's and doctoral degrees in political science from the University of Illinois at Urbana-Champaign.
His wife of 55 years, the former Maude Beavers, died May 19. Survivors include two daughters and two grandsons. His brother died in 2009.