Former Vice President Joe Biden voted to protect the tax-exempt status of privately-owned and operated segregated schools while serving in Congress.

As a second-term United States senator from Delaware in 1979, Biden voted against revoking the “Dorian rider,” a legislative provision that prevented the Internal Revenue Service (IRS) from rescinding the tax-exempt status of private segregated academies. Such schools were founded in the wake of the Supreme Court’s 1954 Brown v. Board of Education decision, which found unconstitutional “separate but equal” public educational institutions that segregated by race.

Biden’s vote on the measure, which put him at odds with then-President Jimmy Carter and such vaulted liberal institutions as the American Civil Liberties Union (ACLU), was first reported by the Washington Free Beacon on Wednesday.

At the time of the vote, Biden was seen as one of the senate’s leading opponents of busing to desegregate public schools. The issue was particularly volatile for his constituents in Delaware, especially in the state’s largest city, Wilmington. As late as 1981, the city’s only public school district was redrawing its boundaries, intermixing urban and suburban neighborhoods.

Biden, although seen as a liberal on civil rights, sided with his constituents, even going to the extent of supporting a constitutional amendment to ban busing in 1975.

Portions of that record were put on display last year during the the first Democrat presidential debate when Sen. Kamala Harris (D-CA) confronted  the former vice president on the topic.

“There was a little girl in California who was part of the second class to integrate her public schools and she was bussed to school every day. That little girl was me,” Harris said. “So I will tell you that on this subject, it cannot be an intellectual debate among Democrats. We have to take it seriously.”