Barack Obama has made a rare intervention in the 2020 White House race to blast a "despicable" racially charged attack ad against Joe Biden.
A pro-Trump group put out the clip that twists Obama's own words in order to undermine the Democratic contender.
The clip was called South Carolina, Joe Biden Can't Be Trusted. Katie Hill, Obama's communications director, said in a statement "this despicable ad is straight out of the Republican disinformation playbook."
Biden is hoping the black vote in South Carolina's primary on Saturday will revive his campaign.
Obama has observed neutrality in the race, refusing to endorse a contender.
Hill reiterated that Obama "has several friends in this race, including, of course, his own esteemed vice-president", but "has no plans to endorse in the primary".