The Rev. Jesse Jackson Sr. has signed on as a special adviser to Sen. Bernie Sanders’ presidential campaign, getting the Vermont senator to make several promises to Black voters.

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Jackson said Sanders promised to introduce a constitutional amendment in Congress next week on the right to vote. Jackson also said Sanders committed to expanding Pell Grants, nominating a Black woman to the Supreme Court and naming a Black woman to his cabinet, should he become president, reported CBS News.

Jackson, who endorsed Sanders (I-VT) just before last Tuesday’s Democratic primary in Michigan, also asked Sanders to choose a Black woman running mate and said Sanders promised him he would give the request his “highest consideration.”

Over the weekend, Sanders tweeted his admiration of Jackson.

“I’m humbled and proud to have Rev. Jesse Jackson, Sr. by my side in the fight to expand voting rights, create a single-payer health care system, and finally deliver full social and economic equality for those who have been left behind,” Sanders tweeted on Saturday.

Jackson, a civil rights activist, ran for president in 1984 and 1988. Sanders supported his 1988 presidential campaign over Biden’s. In a statement, Jackson said Sanders had asked for his endorsement but that he was never asked by Biden’s campaign for his support, CBS News reported.

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It is unclear what difference Jackson will make in Sanders’ campaign in the upcoming primary races. So far, in previous primaries, Biden has captured the majority of Black voters’ support. The former vice president won the Black vote handily in South Carolina, and on Super Tuesday, he won southern states with sizable Black populations.

As special adviser for economic and foreign policy, Jackson will help Sanders enact a federal jobs guarantee and put an end to wars, according to a statement put out by the Sanders campaign.