We are counting down to the start of what will be a truly historic

Democratic National Convention. President Biden just moments ago arriving

here at the United Center for a walkthrough, saying he's ready to pass the

torch to his Vice President Kamala Harris.

It was just a month or so ago that Biden was supposed to headline his party's convention.

Welcome to our viewers in the United States

and around the world.

This is a special edition of the Situation Room.

We're live from Chicago.

I'm Wolf Blitzer.

And I'm Aaron Burnett and you know Wolf

while there is energy and excitement for the Democrats here in Chicago the next few

days are going to serve as a significant test for the Vice President

Kamala Harris defining her candidacy.

She has a candidacy that's four weeks and one day old and tonight the person tasked

with helping her accomplish that is President Joe Biden.

Harris will be in the room watching as Biden is expected to use his prime time address

to make the case that his Vice President is the best candidate.

We're also going to hear from the first lady, Jill Biden, expecting

to pay a tribute to her husband calling on Americans to rally behind Harris. And also, among the

headliners tonight, Wolf, the former Secretary of State Hillary Clinton will also be speaking.

Lots of important speakers coming up not just tonight but throughout the week.

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