GEOFF BENNETT: All night, we will# be digging into data from some of## the battlegrounds and key races of this election.

For a deep dive into all of that,## we're joined now by our Lisa Desjardins# over at the PBS News super screen.

All right, Lisa.

So let's start with the# big state everyone is watching tonight,## Pennsylvania.

What counties are you tracking?

LISA DESJARDINS: I'm sad we have# to pick just a couple to highlight,## but it is Election Day.

So it's all about choices.

And let's start here in Philadelphia, the most# important county for Democrats.

Let me show## you what happened here between 2016 and 2020.# Hillary Clinton, 83 percent, but that actually## went down for Joe Biden, 81 percent.

That's great# in any county.

But when it's your biggest county,## this is a place where Kamala Harris needs to do# more like Hillary Clinton than like Joe Biden.

Let's look at somewhere that the Trump# campaign is paying attention to.

This## is Berks County.

What's there?# This is where Donald Trump ended,## had his last rally in Pennsylvania last night, a# place known and loved by the Desjardins family.

And I want to show you what's going on# here, why the margins in Berks County## matter.

Donald Trump actually had about the# same margin between 2016 and 2020.

But look## at this.

Joe Biden gained percentage in this# county.

Also paying close attention to Berks## County because its population, 25 percent# Hispanic, including many Puerto Ricans.

We want to see there's any effect from those## remarks from the Trump rally# earlier, a couple of weeks ago.

AMNA NAWAZ: Lisa, we know we could have# a long night ahead.

So what are some of## the places you're tracking that could give us# some of the earliest look at what's to follow?

LISA DESJARDINS: Georgia is one of the# states we expect to hear from first,## especially these -- some of# these counties around Atlanta.

Let's talk about Gwinnett County.# This is a place that used to be red,## now has voted more blue.

Also Cherokee# County, this is somewhere -- we're going## to talk a lot about not just who wins these# counties, again, but the margins.

This is## somewhere we saw the Biden campaign lost,# but still did better than Hillary Clinton,## the kind of place that we think that the# Harris campaign needs to do as well as Biden.

Trump hopes to do better than he did last# time.

Let's look at North Carolina.

There's a## couple of population centers that we will watch# early in the night, Raleigh, Charlotte.

Those## counties, Wake County and Mecklenburg County,# the turnout in those counties are going to## be important for Democrats.

Heavy turnout there# would be good news for Democrats across the state.

GEOFF BENNETT: So, we talked to you earlier about## Pennsylvania.

What about the# rest of the blue w.. LISA DESJARDINS: Yes, the blue wall is critical# for Democrats, and it's something that,## of course, Republicans want to cut into# tonight, as they were able to in 2016.

Let's look at Michigan.

Some place# that I will be watching very closely,## here's Detroit.

Right next to Detroit, we have# Washtenaw County.

That's Ann Arbor.

This is a## place that was sort of a hotbed of protest against# the Biden administration policy in Gaza and the## Middle East.

And we have to see if there is a# kind of backlash against Kamala Harris there,## maybe third-party voting there.# So we will watch that carefully.

Let's talk about Wisconsin, and about the# same sort of area of Wisconsin.

You have## got Milwaukee right here.

Want to point out# another county right there, sort of a bedroom,## suburb, exurb county.

That's Waukesha# County.

And here is another place where## we need to watch the margins.

It's not just# about who wins.

This is a Republican county.

But look at this.

Again, this is# a place where Biden was able to## cut into what Trump did in 2016.

The question is,## can Trump regain momentum there?

Or does --# Harris be able to perform as well as Joe Biden?

AMNA NAWAZ: And, Lisa, we know you're# tracking the races that will decide## control of the House and the Senate# as well.

Tonight, tell us about that.

LISA DESJARDINS: You know I# love some congressional numbers.

All right, let's talk about the Senate.

We start## right here with these races that are# not even up this year.

The Senate,## about a third of it is up for reelection every# two years.

So look at this.

Republicans have 38## seats in the bank.

Here's where that halfway# point is.

So they start out with an advantage.

But here's where we will be watching early# as to our question, races like in Ohio with## Sherrod Brown, Pennsylvania, Wisconsin,# and then a really key one will be Montana,## where Jon Tester is fighting for his life.# Those polls close there at 10:00 Eastern time.

Let's look about the House, so# many races to talk about.

But## we're going to keep track of it# all night in part by looking at## these eight races that will show us sort# of who's up and who's down.

Democrats,## again, need to pick up about four seats.

And we# will be watching these that close around 7:00## and these ones that close around 9:00 Eastern# just to help us keep track of where we are.

AMNA NAWAZ: All right, Lisa Desjardins# over at the PBS News super screen,## where she will be for the rest of the night.

Lisa, thank you.