starts at 8:00 p.m. Eastern on PBS stations.

For a preview, "NewsHour" political correspondent Lisa Desjardins is in Los Angeles with a roundtable

of guests.

And, Lisa, it seems like I was just talking to you from the Capitol about the impeachment

vote, and now you're out there.

Could you just not -- you just couldn't wait to get out of town after last night?

(LAUGHTER)

LISA DESJARDINS: Well, you can't accuse "PBS NewsHour" of being on just one coast.

We hit both coasts within just 12 hours.

And I think, John, as our viewers know, that's just how the news is these days.

You're the same way.

How many topics are you covering in a single show?

We have to travel.

And the stories are moving faster than we can, almost.

JOHN YANG: Absolutely.

But you keep up with them, Lisa.

That's the difference between you and me.

You keep up with them.

LISA DESJARDINS: We try.

JOHN YANG: And, sometimes, you keep ahead of them.

(LAUGHTER)

LISA DESJARDINS: We try.

But I'm also very fortunate.

To help us through this debate tonight, we have an esteemed panel.

They will be with me now, also through the entire debate.

Let me introduce our wonderful anchor of "NewsHour West," Stephanie Sy, next to her, friend of

"NewsHour" Amy Walter, of course, of Politics Monday and The Cook Political Report.

Next to her, we have Ryan Lizza of Politico, and, of course, Laura Barron-Lopez also, national

political correspondent for Politico.

Ladies and gentlemen, I have a question for you.

With all of this news, how do any of these candidates stand out, get any attention tonight?

Stephanie, what could happen here that could get some voters' attention?

STEPHANIE SY: You know, I think a lot of voters are actually paying attention to these debates,

because a lot of them are undecided.

So, I think, really, for these candidates to stand out, it has to be about policy, and

it has to be about personality.

I mean, let's not kid ourselves.

The first of the voting is less than two months away.

There are still so many people that don't know who they're voting for.

So, I think the candidates that really resonate are the ones that can connect on a deeper

level.

You know, I think they want to get to know people.

We did a poll, PBS/NPR/Marist, last week that showed most Democratic voters care about most

about the candidate that can beat President Trump, vs. the candidate that they identify

with policy-wise.

So I know a lot of the Democratic voters I spoke to recently, they are picturing which

are these candidates looks presidential and they can picture on a debate stage, if there

is a debate, with President Trump.

AMY WALTER, The Cook Political Report: With President Trump, yes.

That's a good point.

LISA DESJARDINS: Amy, I saw you nodding about that.

You know these elections in and out.

We're 46 days, as Stephanie alluded to, from the Iowa caucuses.

AMY WALTER: Right.

LISA DESJARDINS: Believe it or not, people, we're there.

AMY WALTER: And it's the...

LISA DESJARDINS: Where it where is the voter mind-set, the undecided voter mind-set now?

AMY WALTER: Well, the undecided voter mind-set, of course, is thinking about holiday shopping.

(LAUGHTER)

AMY WALTER: Which I have not done yet.

Sorry, everyone on my list.

LISA DESJARDINS: Come on.

(LAUGHTER)

AMY WALTER: I know.

It's still -- so, this is both -- it's a good time and a difficult time for these candidates,

not just the deluge of news, but people are literally traveling everywhere and getting

their focus on family and holidays.

But, look, this is the last time that these presidential candidates are going to have

a national audience before we hit the Iowa debate in the middle of -- in the middle of

January, which is only a couple weeks before the Iowa caucuses.

And the other thing, Lisa, as you very well know, a lot of the folks who are sitting on

the stage may be spending some of their January, a lot of their January, stuck in Washington

at an impeachment trial.

And so the fact that this may be the last time for a while that we will see all of them

together -- and I think Stephanie makes a good point.

As they're all -- these are the top -- these are the top candidates all in one place.

The fact that it's a smaller field means that we could probably get more of a robust discussion

than you could get with 10 or 12 candidates on stage.

LISA DESJARDINS: And let's look at this small field tonight, the smallest field we have

seen on stage, seven candidates tonight.

That's down from 10 in the last one.

Let's look at the lineup that we have got.

These candidates will be on stage in order, roughly, by their polling, with the highest-polling

candidates in the center.

That is former Vice President Joe Biden, Vermont Senator Bernie Sanders and Massachusetts Senator

Elizabeth Warren.

They will be flanked by the other candidates who met the tougher qualifications for this

debate, going left to right, Andrew Yang.

Then we have got former Indiana Mayor Pete Buttigieg, then, on the other side, another

senator, Amy Klobuchar of Minnesota, and another businessman, Tom Steyer.

Ryan Lizza...

RYAN LIZZA, Politico: Yes.

LISA DESJARDINS: ... what lineups are you interested in looking at?

Who will engage with each other, do you think, tonight?

RYAN LIZZA: Yes.

LISA DESJARDINS: What are the important points of differentiating that we could see?

RYAN LIZZA: Yes, you have a real dogfight in the two early states, with those four candidates

in the center basically being bunched up very close to each other.

You could make a case for any of those four winning Iowa, winning New Hampshire.

I remember covering the 2004 primary, and John Kerry, who went on -- went on to win

Iowa, was at about 3 percent in one poll at this point in 2003.

So, I will be looking for how -- the two candidates on the left ideologically, not on the stage

left, Warren and Sanders, do they start to differentiate themselves a little bit?

They have had this kind of funny nonaggression pact between the two of them.

So I will be looking for that.

Does Biden, the national front-runner, take some incoming?

Do people feel like they need to start dragging him down?

Bernie Sanders, who's back in second place nationally, he has not really been the subject

of much criticism on these debate stages.

Does he start to take some fire?

And then, finally, Pete Buttigieg, who has been the aggressor in the last couple of debates,

is a very gifted debater, a very gifted communicator.

Where does he -- he's going to -- if the past is any -- is predictable, he will go after

someone tonight.

Will it be Biden?

Will it be Sanders?

Will he continue on his sort of jihad against Warren?

So, those are the main things looking at.

AMY WALTER: Yes.

LISA DESJARDINS: Laura, do you agree?

Or does Pete Buttigieg have too much to lose now, now that he's obviously -- he's right

near the top in Iowa, he's trying to regain momentum?

LAURA BARRON-LOPEZ, Politico: I think he still needs to differentiate himself or still draw

those contrasts, potentially maybe with Biden, right, because they pull from each other.

Well, they have -- they're trying to carry the same message forward.

They're trying to both carry this moderate mantle all the way through.

What I'm waiting for is to see if Buttigieg and Warren get into it, because, in the last

month, they have started to attack each other more directly, warren specifically, who Lizza

mentioned the nonaggression pact.

Warren also had this rule that she wouldn't specifically attack Democrats by name.

She would draw subtle contrasts.

She changed that this last month by directly naming Buttigieg and Biden.

And so whether or not, if she's attacked on the debate stage, she decides to very directly

draw those contrasts -- I don't necessarily think she and Sanders are going to go after

each other.

She has sworn consistently that she will not go after Sanders directly at all.

LISA DESJARDINS: Yes, Amy.

AMY WALTER: Well, I just want to bring up something that Stephanie talked about earlier,

this idea about who can beat President Trump, right?

Who's the strongest candidate there?

If you look at the polling we have seen come in, in this last week, really, as impeachment

is coming to a vote, what you find is that the president's job approval rating has actually

ticked up a bit.

Now, it's still not great.

He's still averaging...

LISA DESJARDINS: Clinton's rose a lot during impeachment.

AMY WALTER: This one -- this -- he went from averaging about 41 percent to averaging 43

percent.

So this is very minor.

But, again, if you're...

LISA DESJARDINS: It's not going down.

AMY WALTER: If you're making the case that the most important thing for those folks on

the stage to prove is that they can beat a candidate who is a president in a good economy,

another poll that came out this week showed that the president's handling of the economy,

job approval on the economy, highest it's been it since going back to the beginning

of the year.

So I think this case to be made about -- for these candidates tonight, the case to be made

about, look, he's going to be tough to beat, this is a sitting president, sitting presidents

are difficult to beat -- it's difficult to beat sitting presidents when people feel like

that president is doing a good job on the economy.

Optimism about the economy is as strong as it's been in about 10 or 15 years, maybe a

little bit longer.

Who's going to be the one to be able to have the discipline and the strength to go one-on-one

with him?

LISA DESJARDINS: Another difference about tonight's debate, not only will it have the

fewest number of candidates on stage, but this is the "PBS NewsHour"/Politico debate.

And we know Judy Woodruff has said that she wants this to be about substance.

Now, I think you hear that a lot, but, to me, that means issues.

And we -- and I'm wondering, Stephanie.

You have been talking to a lot of voters.

How do you think voters feel the economy, especially Democratic voters, climate change

-- where are these issues?

What issues do voters care about right now?

STEPHANIE SY: Well, I think the economy is always tops with all voters.

If we're going to look at what is unique to Democratic voters, climate change, especially

in California, factors very high on that list.

But my question is, how do these candidates differentiate themselves on that issue?

Several of the candidates on stage have adopted the basic Green New Deal policies.

And so is that a place where they're going to be able to differentiate themselves?

One of my questions is, as we all know, even if the Democrats are able to win the White

House and both houses of Congress, we're looking at probably whoever is president getting through

one major piece of legislation.

Obama chose to do health care.

He wasn't able to deliver cap and trade.

So, I think, for a lot of California voters, climate change is their number one issue.

But when I was going around talking to voters in the last few days, they all still talk

about how expensive their health care is.

And we -- and that is going to be a major issue, I think, that we will see delineated

between these candidates, is that question of the private option vs. Medicare for all.

I still think that is a major fissure among these candidates.

RYAN LIZZA: Yes.

Yes.

LISA DESJARDINS: Ryan Lizza, we were talking about this earlier.

Talk a little bit more about Elizabeth Warren and sort of the needle she is trying to thread

right now.

RYAN LIZZA: Yes, I completely agree with that.

I mean, health care is always at the top of issue polls of Democrats.

It has been for the last couple of years, and so health care, health care, health care.

I know a lot of people who watch these debates have -- some reporters have been frustrated

by huge chunks of time spent on health care, but that is the issue that Democrats say they

care about.

And I think, if you look at the arc of these debates from the summer until November, you

started with this sort of consensus on Medicare for all.

That looked like the -- where it was the sweet spot in the Democratic primary.

And, slowly, the arguments from the more moderate candidates has started to resonate.

The polls of single-payer among Democrats, not just the broader public, has started to

look a lot more favorable for the -- Pete Buttigieg-Biden version of Medicare for all,

Medicare for...