Rev. Jesse Jackson officially endorsed Sen. Bernie Sanders for president on Sunday during a rally in Grand Rapids, Michigan.

"With the exception of Native Americans, African Americans are the people who are most behind socially and economically in the United States and our needs are not moderate," Jackson said in a statement.

The endorsement is a much-needed boost for Sanders as Biden has already received the support of several of the Democratic nominees after they dropped out of the race.

"A people far behind cannot catch up choosing the most moderate path. The most progressive social and economic path gives us the best chance to catch up and Senator Bernie Sanders represents the most progressive path. That's why I choose to endorse him today."

"The Biden campaign has not reached out to me or asked for my support. The Sanders campaign has, and they responded to the issues I raised," Jackson said.

"He was put on the ticket to balance the ticket, not to enhance it," Jackson said about President Obama's decision to choose Biden as his VP. "Barack was against the Iraq War, he was for the Iraq War. Barack was against the crime bill, he was for the crime bill."

Sanders was elated to have the cosign from his longtime friend.

"It is one of the honors of my life to be supported by Rev. Jesse Jackson, a hero to me who has put his life on the line for 50 years fighting for justice," he tweeted.

"Together, we can, we must and we will defeat the most dangerous president in the history of this country."