Barack Obama, the 44th U.S. president and a marquee name in Democratic politics, used his well-known rhetorical powers to deliver a thundering endorsement of Democratic presidential nominee Kamala Harris.

Mr Obama will address the party faithful on Tuesday evening.

He is expected to pay tribute to outgoing President Joe Biden, who served as Mr Obama’s vice-president for eight years.

He used his well-known rhetorical powers to deliver a thundering endorsement of the Democratic presidential nominee, Ms Harris.

Mr Obama, who got his political start in Chicago, has kept a low profile since leaving office in January 2017.

But he remained a broadly popular public figure and one of the most powerful voices on the political left.

Mr Obama was first elected in 2008 and was the first black president in U.S. history.

Ms Harris is the first female, black, and Asian American U.S. vice-president. She will be another White House trailblazer should she defeat Republican Donald Trump in November.

No woman has ever been president.

Former first lady Michelle Obama is also set to deliver remarks on Tuesday night, as is Ms Harris’ husband, second gentleman Doug Emhoff.

Ms Harris has wiped out Mr Trump’s lead in national polls since Mr Biden abandoned his campaign and endorsed Ms Harris to succeed him a month ago.

Crucially, she has closed the gap or overtaken Mr Trump in the key battleground states that will determine the outcome of the election.

By the time the four-day convention ends next week, there will be just over 70 days until the election.

As the contest enters its last phases, the party hoped the bash would propel Ms Harris into the autumn.

She is due to take to the convention stage for a speech on Thursday night.

(dpa/NAN)