Presidential candidates Kamala Harris and Donald Trump meeting on the debate stage for the first time.

Kamala Harris. Let's have a good debate.

Have fun. Thank you. The vice President walking to the former President's podium to shake his hand in Philadelphia, the two standing just six feet apart. From the start, the gloves were off.

Tonight, you're going to hear from the same old tired playbook a bunch of lies, grievances, and name calling.

Trump punching back.

She's a Marxist. Marxist. Everybody knows she's a Marxist. Her father's a Marxist professor in economics, and he taught her well.

The stakes could not be higher for tonight's debate. The two candidates locked in a dead heat in polls. The economy and inflation on the top of American voters' minds. Trump laying the blame on the Harris and Biden administration.

We have inflation like very few people have ever seen before. Probably the worst in our nation's history. We were at 21%.

Harris responding.

Donald Trump left us the worst unemployment since the Great Depression. Donald Trump left us the worst public health epidemic in a century.

Like the Trump-Biden debate, tonight, there was no studio audience, and the microphones were turned off.

And remember this, she is Biden. She's trying to get away from Biden. I don't know the gentleman. She says, She is Biden. The worst inflation we've ever had. A horrible economy because Because inflation has made it so bad that she can't get away with that.

Harris responding.

Clearly, I am not Joe Biden, and I am certainly not Donald Trump. And what I do offer is a new generation of leadership for our country.

The debate turning personal.

Donald Trump was fired by 81 million people. So let's be clear about that. And clearly, he is having a very difficult time processing that.

Trump claiming Biden was pushed off the Democratic ticket.

You talk about a threat to democracy. He got 14 million votes, and they threw him out of office. You know what? I'll give you a little secret. He hates her. He can't stand her.

Both candidates getting heated when discussing the issue of abortion, an area of vulnerability for the GOP.

Her vice presidential pick says, Abortion in the ninth month is absolutely fine. He also says, Execution after birth. It's Execution, no longer abortion because the baby is born, is okay. And that's not okay with me. Hence the vote.

Abc News fact-checking the former President.

There is no state in this country where it is legal to kill a baby after it's born.

Harris, after reminding Americans of Trump's role in selecting members of the Supreme Court who overturned Roe v Wade, went on the attack.

I absolutely support reinstating the protections of Roe v Wade. And as you rightly mentioned, nowhere in America is a woman carrying a pregnancy to term an and asking for an abortion. That is not happening. It's insulting to the women of America.

According to a Pew Research Center study, a majority of Americans believe abortion should be legal in all or most cases. President Trump hammering the Biden administration on the border, an area of vulnerability for Harris.

There's never been anything done like this at all. They've destroyed the fabric of our country. Millions of people let in, and all over the world. Crime is down all over the world. Except here.

Harris defending her record, pointing to the bipartisan border bill that Trump killed.

That bill would have put more resources to allow us to prosecute transnational criminal organizations for trafficking in guns, drugs, and human beings. But you know what happened? To that bill? Donald Trump got on the phone, called up some folks in Congress, and said, Kill the bill. And you know why? Because he'd prefer to run on a problem instead of fixing a problem.

At one point, Trump repeating debunk claims claims about immigrants in Springfield, Ohio.

In Springfield, they're eating the dogs, the people that came in. They're eating the cats. They're eating the pets of the people that live there.

I just want to clarify here, you bring up Springfield, Ohio, and ABC news did reach out to the city manager there. He told us there had been no credible reports of specific claims of pets being harmed, injured, or abused by individuals within the immigrant community.

Both candidates going after another, Harris needling Trump about his rallies.

You will see during the course of his rallies, he talks about fictional characters like Hannibal Lector. He will talk about windmills cause cancer. And what you will also notice is that people start leaving to her rallies early out of exhaustion and boredom.

People don't go to her rally. There's no reason to go. And the people that do go, she's bussing them in and paying them to be there.

Abc news anchor Lindsay Dave is challenging the vice president on her changing positions.

Vice President Harris, in your last run for President, you said you wanted to ban fracking. Now you don't. You wanted mandatory government buyback programs for assault weapons. Now your campaign says you don't. You supported decriminalizing border crossings. Now you're taking a harder line. I know you say that your values have not changed. Then why have so many of your policy positions changed?

My values have not changed, and I'm going to discuss at least every point that you've made.

Tonight was crucial for both candidates, but for Harris, it was her biggest stage yet as she reintroduces herself to voters, with recent polls showing nearly a third of voters say they still don't know enough about her. While tonight was her first presidential debate, she did not hold back.

When you then talk in this way in a presidential debate and deny what over and over again are court cases you have lost because you did, in fact, lose that election, it leads one to believe that perhaps we do not have in the candidate, to my right, the temperament or the ability to not be confused about fact.

Trump launching a tax on Harris's record.

She's worse than Biden. In my opinion, I think he's the worst President in the history of our country. She goes down as the worst vice President in the history of our country.

Tonight was Trump's seventh presidential debate. Less than three months ago, he was on the debate stage facing off against a different candidate. With the COVID, excuse me, dealing with everything we have to do with, Look, if we finally beat Medicare. Shortly after Trump survived an assassination attempt, then Biden, dramatically ending his bid for a second term, passing the torch to his vice President. Polling shows Harris and Trump locked at a tight race. A New York TimesCieno poll found Trump leading Harris by one percentage point. The former President's support holding steady despite a New jury finding him guilty on all 34 counts of falsifying business records in the Sturmy Daniels hush money case.

I think this is so rich coming from someone who has been prosecuted for national security crimes, economic crimes, election interference, has been found liable for sexual assault, and his next big court appearance is in November at his own criminal sentencing.

Trump responding.

I'm winning most of them. But those are cases. It's called weaponization. Never happened in this country. They weaponized the Justice Department.

It's nice debate coming amidst prolonged conflict in the Middle East. Israel, a controversial topic.

She hates Israel. If she's President, I believe that Israel will not exist within two years from now. I've been pretty good at predictions, and I hope I'm wrong about that one. She hates Israel.

Vice President Harris, he says you hate Israel.

That's absolutely not true. I have my entire career and life supported Israel and the Israeli people. He knows that he's trying to, again, divide and distract from the reality, which is it is very well known that Donald Trump is weak and wrong on national security and foreign policy. It is well known that he admires dictators, wants to be a dictator on day one, according to himself.

After the debate, Taylor Swift endorsing Harris, writing in part on Instagram, I'm voting for Kamala Harris because she fights for the rights and causes I believe need a warrior to champion them. With the election less than two months away, the impact of tonight's debate can't be underestimated.

What matters is what the voters think. But in the end, right now, he is tied with Kamala Harris. Does this change anything? You have to be very careful, and it's very important to see what the voters think.

We come back, our Powerhouse Roundtable drills down on the action of the evening and tells us what it all means as we move through this contentious and consequential presidential election.