GEOFF BENNETT: And Lisa Desjardins joins us now at the super screen for a deeper dive into the battle for the House of Representatives.

So, Lisa, this is an expensive contest for the House.

Where does it all stand?

LISA DESJARDINS: Expensive and expansive.

Look at this map of all the races.

These are the 81 somewhat to very competitive races that we are tracking.

Now, The Cook Political Report lists a lot of competitive races.

It's important to also know this number, three.

This is the magic number.

Democrats need to flip three seats on net in order to take over the House.

So I don't want to just look at this large map, but let's look at the most competitive seats that are toss-ups or leans.

These 50 dots represent those 50 seats that may determine the fate of the House of Representatives.

What's important here is who occupies them now.

Look at this.

It's mostly Republicans, 39 of these seats occupied by Republicans.

They are on defense.

Remember that magic number three?

So, essentially Democrats need to pick up three seats right here -- this is the line -- in order to flip the House.

Now, The Cook Political Report already forecasts that Democrats are likely to flip some seats.

How many?

Ten.

So, if you remember this line that determines control of the House, Democrats have already put themselves in position to pass that.

And, right now, Republicans need to push back.

But they are in a good position at this moment, Geoff.

GEOFF BENNETT: And on the substance of all these races, the economy is the top issue, per usual.

But how and where is that playing out?

LISA DESJARDINS: Right.

I love looking at this the substance.

Let's talk first of all, about housing, that issue that we found in Northeastern Pennsylvania.

These are the places where housing is particularly an issue in the campaign.

You see it in Florida, in Nevada, in Southern California.

But let's talk about the issue that a lot of Americans also feel, gas and fuel prices.

It is everywhere, but I want to point out these races where they are particularly facing record high fuel prices, or like in Maine or Alaska, where they are more dependent on diesel or heating oil.

And let's focus on one race in particular where this is a factor.

Let's go to Colorado's Eighth District.

This is a situation where the gas prices have still been rising this month.

The Democrat, Manny Rutinel, says that the issue is Iran and tariffs.

He says he had pushed back against President Trump.

But the Republican, Gabe Evans, says, no, it's the problem of regulation, and he has supported President Trump.

So this is a factor in this race.

GEOFF BENNETT: And what about the other issues driving these midterm races?

LISA DESJARDINS: There's one more I want to talk about because a lot of the country is, and that is data centers.

Here's an example of four of the races where that has become a campaign issue this year.

And I want to focus on one.

This is Central Michigan, Michigan's Seventh District.

The Democrat, Will Lawrence, won his primary in part because he campaigned so hard on a ban, at least temporarily, on data centers.

This is a district where we just saw a $10 billion data center put on hold because of protests from locals.

Now, Tom Barrett, the Republican incumbent, he has a different tact.

He instead says each locality should be able to decide whether they want the data center or not.

This race is a good test of how far voters want to go when it comes to data centers.

And all of these issues, of course, around the country do have ties to the economy.

And it's important to see how that layers in.

GEOFF BENNETT: Lisa Desjardins, our thanks to you, as always.

LISA DESJARDINS: You're welcome.