GEOFF BENNETT: Last night's debate may be the first time that millions of Americans have paid attention to the presidential campaign this year, and they heard a lot of claims that have been familiar refrains on the campaign trail, not all of them true.

To help put it into context.

We turn to Samantha Putterman of PolitiFact.

Sam, thanks so much for being here with us.

SAMANTHA PUTTERMAN, PolitiFact: Thanks for having me.

GEOFF BENNETT: So let's take some of these debate topics one by one, starting with the economy and inflation.

Donald Trump said that President Biden caused inflation and that the cost of food doubled and tripled and quadrupled, while President Biden says that Trump's proposed 10 percent tariffs would cost the average American $2,500 a year.

Help us understand what's true.

SAMANTHA PUTTERMAN: So, on Trump's claim that Biden inherited inflation, that's mostly false.

When Biden was inaugurated, inflation was about 1.4 percent, but that was shaped by the still weak economy during the pandemic.

As pandemic conditions improved, the economy accelerated, leading to inflation peaking at 9 percent about a year-and-a-half into his presidency.

That was the highest in about four decades.

But economists say that his relief plan did exasperate inflation, but he didn't single-handedly cause it.

And on Trump's claim that food costs has doubled, tripled and quadrupled, we found that to be false.

Food costs have risen faster under Biden, but the 21 percent increase is nowhere near what Trump claimed.

That would need to be about 300 percent, which is 10 times larger than what Trump said.

And Biden's claim about Trump's proposed tariffs costing Americans $2,500, we found that to be mostly true.

Economists expect that Trump's proposed 10 percent across-the-board tariff on foreign products will force consumers to pay more and ride around that range between about $1,700 and $2,500.

GEOFF BENNETT: Got it.

So let's turn to immigration.

Donald Trump said that President Biden has allowed in 18 million people and that they're coming from -- quote -- "prisons, jails and mental institutions."

President Biden says there are 40 percent fewer people coming across the border illegally.

What do we know about the situation on the southern border?

SAMANTHA PUTTERMAN: Right.

So Trump's claim about the millions of people coming from prisons and mental institutions, we found that to be our worst rating, Pants on Fire.

Data shows that officials have arrested a little over 100,000 noncitizens with criminal convictions from 2021 to 2024.

Not everyone was let in.

The data reflects the people that the government knows about, but it's inexhaustive.

So immigration experts did say that, despite these limitations, there's no evidence to support his statement.

And also we rated false his statement that Biden has allowed in 18 million people.

Immigration officials have encountered immigrants illegally around 9.7 million times under Biden's presidency.

While counting for got-aways, that number rises to about 11.4 million.

But encounters do not equal admissions.

Encounters represent events, not people.

So one person who tried to cross the border twice counts for two encounters.

And a lot of these also led to expulsions.

And on Biden, he was more accurate on immigration.

His 40 percent claim is mostly true.

DHS announced that encounters dropped by 40 percent to fewer than 2,400 per day in the weeks after Biden announced his policy on June 4.

GEOFF BENNETT: On abortion, Mr. Trump repeated a false claim that he's made before that Democrats, in his words, will take the life of a child in the eighth month, the ninth month, and even after birth.

Help us understand this, because willfully terminating the life of a newborn is illegal in every state.

SAMANTHA PUTTERMAN: Right, right.

So we did find this to be false.

Most elected Democrats who have spoken publicly about this, they have said that they support abortion under Roe v. Wade's standard, which provided access up to fetal viability, typically considered around 24 weeks of pregnancy.

And many of these Democrats have also said that they support abortions past this point if the treating physician deems it necessary.

So medical experts say situations resulting in fetal death in the third trimester are rare.

It's less than 1 percent of abortions that occur after 21 weeks.

And these cases typically involve fatal fetal anomalies or life-threatening emergencies affecting the pregnant women.

GEOFF BENNETT: You know, the CNN moderators last night did not provide real time fact-checking.

The network said that they didn't view that as their role.

Their role was to facilitate an exchange of ideas, and it was up to the candidates to challenge one another.

That was an approach that both campaigns agreed to.

What's the consequence when a torrent of lies and mistruths delivered with verve and vigor go unchallenged as they were last night?

SAMANTHA PUTTERMAN: Yes, I think that the consequences are quite high.

This was on the biggest political stage thus far in this presidency.

And, of course, I would say that fact-checking is important.

I understand the moderators wanted to make sure that the candidates got their say in and to not appear like they were unfairly interfering or favoring one side over the other.

But as journalists, it's also their job to hold powerful people accountable and check them when they are being inaccurate with the American people, especially during a high-stakes presidential election.

I don't think they could have fact-checked every false or misleading claim made last night, but they could have done their due diligence to correct for the record frequently false claims made on incredibly important topics like abortion, economy, and immigration.

The American people deserve to know when a presidential candidate is spreading falsehoods, especially on issues they will be voting on.

GEOFF BENNETT: That is Samantha Putterman of PolitiFact.

Sam, thanks so much.

SAMANTHA PUTTERMAN: Thank you.

GEOFF BENNETT: And you can find more debate fact-checks from PolitiFact on our Web site.