GEOFF BENNETT: And for more on the latest in the presidential race, including a look ahead to tomorrow night's debate, we're joined by our Politics Monday duo.

That's Amy Walter of The Cook Political Report With Amy Walter and Tamara Keith of NPR.

Great to see you both, as always.

TAMARA KEITH, National Public Radio: Good to be here.

GEOFF BENNETT: So tomorrow is the first and so far only debate between Kamala Harris and Donald Trump.

This is a potential campaign reset moment as many voters tune in for the first time with, what, 56 days left to go until Election Day, but who's counting?

So, Tam, how are both sides preparing?

TAMARA KEITH: Well, one thing that has stood out to me today for hearing from both campaigns is that they are both talking up Donald Trump's ability to debate.

Both the Harris campaign and the Trump campaign say that he's hard to debate, that he has a lot of experience debating.

They have different reasons for doing this, but essentially the Harris campaign is sort of talking down -- they're not talking down her ability, but they're just tempering expectations, because she's this person who, as a former prosecutor, had these standout debate moments.

She, in various Senate hearings, prosecuted the case, asking tough questions.

And her campaign is trying to say, temper those expectations.

Trump is this unique person who is difficult to debate, who is unencumbered by facts, as she says.

And so watch out.

That's a little bit of working the refs, I think, from both of the campaigns and -- yes, so working the refs.

And the other thing that I will say is that what we know is that Harris is new in the spotlight.

She has not been running for president long.

A lot of people didn't get to know her when she was vice president.

And so this is a very high-stakes debate for her to introduce herself to voters.

Trump is well-introduced.

People know who he is.

Her campaign would like to remind people of some of his flaws, but those flaws may not be as on display as some of her supporters would like.

GEOFF BENNETT: And, Amy, for that reason, you can argue that Kamala Harris and Donald Trump are in many ways speaking to different audiences or trying to reach different parts of the electorate.

What constitutes a win tomorrow night for Trump and for Harris?

AMY WALTER, The Cook Political Report: The whole -- I think Tam said it quite well at the end there, which is this is all about defining Harris, this entire debate.

It's very hard to see that people are going to walk away from the debate saying, I feel so much differently about Donald Trump than I did a day ago, right?

Those are pretty locked in.

But, for Harris, she really does have to speak to those swing voters who have -- maybe they voted for Biden in 2020, but haven't completely come back into the Harris camp or into voting against Donald Trump again.

And they do -- they want to understand who she is, what she's going to do for them.

So to the point that Tam made about lowering expectations, I think for a lot of partisan Democrats, what they would like to see is the Kamala Harris that showed up in the Supreme Court hearings going after and, as one Democrat said to me, just having a takedown of Donald Trump.

That is not what Kamala Harris needs to do.

She needs to be speaking to an audience that isn't interested in her taking down Trump, but they want to know what is she going to do for them.

For Trump, talking to Republicans today, his top priority is stick to the issues, stay away from the personality.

Now, we have known that that's not always easy for him to do, but that is -- they feel like he has a pretty easy job is if he sticks to substance that he can make a good case for why Harris should not get four more years.

GEOFF BENNETT: We will see if that happens tomorrow night.

Can we talk about this New York Times/Siena College poll that has political obsessives all spun up?

Because it shows that the race is basically tied nationally, unchanged since President Biden was in the race.

And the battleground polls show basically the same thing.

The biggest lead that Harris has is in Wisconsin, which is by three points.

But the takeaway here, Tam, is that this is an agonizingly tight race.

TAMARA KEITH: Yes, absolutely.

And it has been all along.

Certainly, Harris is performing better than President Biden was in the month of July.

However, this is just a really close race.

If you remember, the presidential election was decided by a small number of votes in a small number of states in 2016 and again in 2020.

And so both of these campaigns are really set up to face that again.

I think that's partially why you see Trump now sort of talking about election fairness and possible election denialism, again, sort of laying the groundwork.

And it's why you hear Harris talking about herself as an underdog, in part because she needs voters to be so motivated to show up to vote that even if they have to pick the kids up from school and go pick up groceries, they're still going to go vote.

AMY WALTER: Yes, so part of the reason - - this is a national poll.

And I think part of the reason that you're hearing sort of this consternation, especially for Democrats, is they look at the results of the last two elections.

Hillary Clinton ultimately won the national popular vote by about two points.

She lost narrowly in those key swing states.

Biden was leading, won the popular vote by four points, narrowly won.

So if you are Kamala Harris, and you're either trailing by one or you're just up by one, that is lower than where Hillary Clinton was.

And the other -- and certainly much lower than where Biden was.

The other question I think a lot of folks are having is, OK, if the polls were off in 2016 and 2020 by undercounting Trump supporters, are these polls finally getting it right and showing, as Tam said, a race that we should know all along is tight, or should we see that it is actually going to undercount him again, he's actually ahead by four?

(CROSSTALK) GEOFF BENNETT: Because there have been Democrats who've said that this poll in particular oversampled Republicans and in a way that could mean that it's actually more correct.

It's a more accurate sample.

AMY WALTER: Or we just accept that.

TAMARA KEITH: Or it's not.

(CROSSTALK) GEOFF BENNETT: Or it's not.

AMY WALTER: Or we just accept, as we have for a long time, that this is, I think you said agonizingly.

This is going to be very, very close.

And right now this is why this debate is so critical.

I think what you saw from the moment Biden dropped out and through the convention, Harris got all that support among Democrats and Democratic-leaning independents, and the race has sort of stalled out there.

Trump hasn't lost anything, but he hasn't really gained anything and the debate becomes a moment where it can.

TAMARA KEITH: Yes, and all of this essentially tells us that all of that euphoria that Democrats felt with Harris coming on, that didn't actually change the fundamentals of the race.

Her support is consolidated in a way that Trump's has been all along.

AMY WALTER: Yes.

GEOFF BENNETT: All right, Tamara Keith and Amy Walter, thanks so much.

Appreciate it.

AMY WALTER: You're welcome.

TAMARA KEITH: You're welcome.