Harris spent her closing statement seeking to draw a final contrast between her vision for the country and that of Trump.

She also sought to take a moment to introduce herself to viewers who may not be familiar with her policies and resume, highlighting her background as a prosecutor, California attorney general and U.S. senator.

"We're not going back," she said. "And I do believe that the American people know we all have so much more in common than what separates us, and we can chart a new way forward."

Fact Check: Needs context

The U.S. budget for clean energy investments (over $559 billion as of August 2023) is the largest in the world, according to the World Economic Forum. About a third of that investment is going toward low-carbon electricity projects, and about a quarter is aimed at developing low-carbon, efficient transportation, according to WEF. In the first quarter of 2024, the U.S. "continued its record-setting growth" with a new high of $71 billion invested in clean energy and transportation, according to Clean Investment Monitor.

At the same time, the U.S. Energy Information Administration reported in March that the U.S. is now producing more crude oil than any country ever has -- and has been for the past six years in a row. In December 2023 the U.S. reached a new monthly record high of more than 13.3 million barrels per day, according to the EIA.

The Harris-Walz campaign told ABC News that the trillion-dollar amount cited by the vice president is based on the total spending of the Inflation Reduction Act, the CHIPS and Science Act of 2022 and the Bipartisan Infrastructure Law. In a statement, they told us "Vice President Harris was proud to cast the tie-breaking vote on the largest ever investment to address the climate crisis and under the Biden-Harris Administration, America is more energy secure than ever before with the highest domestic energy production on record."

Even if you take the lowest estimate for federal spending under the IRA, 780-800 billion dollars, adding the funds allocated in the CHIPS and BIL laws does exceed the $1 trillion figures that Harris has cited in her campaign speeches. All three laws include provisions that address climate change.

The Harris campaign is feeling good about the debate so far and how Harris has put Trump on defense.

“VP Harris is in total command of the stage. She is presidential. She has Trump on the ropes, holding him accountable for his own actions -- notably how he got Roe v. Wade scrapped and the damage that's caused women across America. He hasn't been the same since that exchange,” Harris campaign spokesperson Ian Sams said on X.

The Harris campaign is also getting reaction from a focus group of undecided voters in battlegrounds in real time. These are dial groups that give a number to indicate how they’re feeling about each candidate as the debate goes on.

A campaign official shared that Harris' response on Jan. 6 -- saying it's time to "end the chaos," "turn the page" and return to stability -- was one of the strongest answers of the night among men.

The campaign official also shared that Harris' talking about abortion was a strong moment for her among undecided voters.

-ABC News' Selina Wang

Harris is noticeably more expressive in the room.

While Trump has occasionally smirked or shaken his head, her body language is much bigger, turning toward Trump and back, folding her hands, unfolding them, making faces as if shocked or strongly disagreeing with Trump while he talks.

For example, she looked disgusted when Trump mentioned Hungary's Viktor Orban. When Trump said he was being sarcastic about losing the 2020 election by a "whisker," Harris made a disapproving face, eyebrows furrowed and shook her head. When Trump was talking about Jan. 6, she shook her head throughout.

Trump's biggest reactions so far were around his court cases and when Harris said "you're running against me" (not President Joe Biden). He raised his eyebrows and gave a smile.

-ABC News' MaryAlice Parks