Lucius Barker, political scientist who studied race, civil liberties

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.

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, but for years afterward, he had his students at Washington University and Stanford University take the Louisiana understanding test, as it was called, to demonstrate the obstacles faced by African Americans seeking to vote.

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. He wrote two influential political science textbooks, and his students at Stanford included Sen. Cory Booker, D-N.J., and twin brothers Julián 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, Calif., at age 92. The cause was complications from Alzheimer’s disease, said his daughter Heidi Barker.

Throughout his career, Barker examined the role of the courts in the country’s political system, as well as the political effects of race. 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.

“We tried to make it come alive, to let people know that court cases don’t just spring out of nowhere,” Barker told the Chicago Tribune in 2009.

The book, now in its ninth edition, is still used in college courses and is “a classic, a seminal work,” Duke University professor Paula McClain said in an interview.