Rev. Jackson thinks Obama has been singling out African Americans for criticism, without looking at the larger problems of society.
Rev. Jackson was recorded as saying Obama has been "talking down to black people on this faith-based ... Barack, he's talking down to black people."
Rev. Jackson continued to say he'd like to cut off a certain part of Obama's anatomy.
On Wednesday, Mr. Jackson called his comments hurtful and wrong. He also said he supports Obama's historic candidacy.
"I offer apology for that, because I don't want harm or hurt to come to his campaign. It represents too much of the dreams of so many who paid such great prices," said Rev. Jackson.
Obama's campaign said he "will continue to speak out about our responsibilities to ourselves and each other, and he of course accepts Reverend Jackson's apology."
Jackson's son, Congressman Jesse Jackson Jr., said he was deeply outraged and disappointed in what he called his father's reckless statements and ugly rhetoric.
Jesse Jackson Jr. is a national co-chair of the Obama Campaign.