The Sanders campaign is working past a poor performance on Super Tuesday.

Sen. Bernie Sanders, I-Vt., said on ABC’s “This Week” that he will officially receive the endorsement of Rev. Jesse Jackson at a rally in Grand Rapids, Michigan.

Sanders supported Jackson’s 1988 presidential bid and helped Jackson score a primary win in Vermont. Now, as concerns mount about Sanders ability to garner the support of black voters, Jackson is returning the favor.

“Later on today, we’re going to have the support, I believe here in Grand Rapids, of Jesse Jackson. And, as I think you well know, you know Jesse — Jesse has been one of the great civil rights leasers in the modern history of this country,” Sanders told ABC News Chief Anchor George Stephanopoulos on Sunday. “He changed American politics with the concept of the Rainbow Coalition — getting the blacks and whites and Latinos together in ’84 and ’88. He’s been a leader in helping to transform this country, an aide to Dr. Martin Luther King, Jr., so we’re proud.”

The endorsement comes after a poor performance on Super Tuesday, losing 10 of 14 states to former Vice President Joe Biden, including all of the Southern contests. It also comes shortly after Sen. Kamala Harris, D-Calif., tweeted her endorsement of Biden Sunday morning. She is the ninth former rival to back his presidential bid.

Sanders is focusing his efforts in a state that he won during the 2016 primary — Michigan. His campaign has canceled planned events in Mississippi, Missouri and Illinois to focus efforts on the Great Lake State.

Much of his campaigning in the state has been about bringing out a diverse coalition to vote for him on primary day. Sanders’ campaign hosted an event in the predominantly Arab-American, Muslim community of Dearborn, Michigan. The Detroit suburb heavily supported Sanders in 2016.

“I look around this room and I see people coming from so many different backgrounds. It is beautiful. This is what America looks like at its best,” Sanders said during his Dearborn rally. “The very first thing we do is we bring people together and we stop the divisiveness in this country. Every person in this room, doesn’t matter if you’re Christian, Muslim, Jewish, whatever you may be, you have the same dreams and the same aspirations.”

Sanders also held a town hall in Flint, Michigan, with all-black female participants.

“We have to transform this country and fundamentally reorient our priorities. And the only way we do this is through an unprecedented grass roots movement,” said Sanders. “We are a movement, not just a political campaign.”

Sanders is also invigorating his efforts to reach African American voters, the Sanders campaign hired one of it surrogates, justice reform activist Phillip Agnew, to shore up organizing in black communities. His campaign also rolled out a policy proposal dubbed “The Reproductive Health Care and Justice for All” which aims to tackle issues of access to reproductive health care and eliminate health disparities, namely black maternal mortality rates, which according to the CDC are three times higher for black women than for white women in the United States.

The changes come as concerns mount about Sanders ability to garner a significant portion of the black vote after losses in the South.

Sanders has previously blamed his struggles with African American voters on Biden’s connection to the first African-American president, Barack Obama. In a press conference with reporters, Sanders said there could be other reasons he wasn’t doing well with the voting bloc.

“I can’t give you a definitive answer. I think his ties to Obama is certainly one of the reasons,” said Sanders. “But there may be other reasons as well.”

This is a developing news story. Please check back for updates.

ABC News’ John Verhovek contributed to this report