And good evening from Detroit. We're round two of the CNN Democratic debates is almost here.

I'm Anderson Cooper. Thanks for joining us.

And I'm Erin Bernette and here we are in Detroit in the spirit of hometown hero Joe Lewis.

There is a heavyweight here tonight as well as a lot of challengers who are ready to go.

They have landed punches on in the last time they met.

So the question tonight for Democrats is which Joe Biden will show up.

The one that senators Kamala Harris and Cory Booker knocked around the debate stage in Miami

or the one who made his bones under pressure so many times before that.

That is of course the big question and just one of many things we will learn tonight

on that debate stage.

We also will see how Senator Harris defense renew healthcare plan just rolling out

this week.

And we'll also find out whether vice president Biden's message, his message of moderation

still resonates, especially after last night.

Congress was Elizabeth Warren and Bernie Sanders dominated proceedings last night.

Biden after all of course is according to polls the overwhelming front runner when you

look at those polls both against fellow Democrats and when you look at the one-on-ones against

President Trump even after his performance last time.

But a second shaky debate appearance could change that.

So it is no overstatement to say that the stakes tonight are very, very high.

As we count down to this crucial debate in what will be another pivotal night tonight,

Anderson.

...