Pam Karlan, a Stanford professor and leading scholar on voting rights, argued on behalf of the plaintiffs at Wednesday’s hearing that the state law created an easier path to the polls for older voters, a tacit form of discrimination that disfavored younger voters.

Karlan compared it to a voter literacy test that was struck down by the U.S. Supreme Court in 1915 in Guinn v. United States .

“Oklahoma had a literacy test that the Supreme Court said was totally legitimate,” Karlan said. “But it then gave white voters a workaround, which was the grandfather clause. They could essentially get an easier path to the polls, and the Supreme Court had no problem saying that violated the 15th Amendment.”

Karlan said while she understood the impulse to provide accommodations for older voters, the Constitution does not allow it unless those rights extend to everyone.