President Joe Biden reacted to the debate in a post on X early Wednesday morning.

"America got to see tonight the leader I've been proud to work alongside for three and a half years. Wasn't even close," he said.

Biden was in New York City during the debate and will be attending the 9/11 memorial services at Ground Zero later in the day.

A majority of debate watchers think Harris won the debate against Trump, according to a poll taken by CNN and SSRS after the debate.

On who won the debate, 63% of debate watchers said Harris and 37% said Trump.

The poll has a margin of error of +/- 5.3% points.

CNN said that before the debate, respondents were split 50%-50% on who would win.

In June, their instant poll found that among debate watchers, 33% thought Biden won and 67% thought Trump won.

-ABC News' Oren Oppenheim

Harris put Trump on the defensive early on, claiming viewers were "going to hear from the same old, tired playbook, a bunch of lies, grievances and name-calling." She later took digs at his rallies and was the first to bring up his multiple indictments.

Meanwhile, Trump tried to tie Harris to President Joe Biden as often as he could. "She is Biden," he said as he criticized their economic record.

Harris' gender was not broached during the debate, though her race was. Trump doubled down on false claims about her racial identity, though he said he "couldn't care less."

Read more about the debate highlights here.

During the Harris-Trump face-off, both candidates tried to score points by slinging barbs at each other.

Here are some of their sharp jabs:

Trump: “Wait a minute, I'm talking now, if you don't mind, please. Does that sound familiar?”

Harris: “Donald Trump was fired by 81 million people.”

Harris: “He talks about fictional characters like Hannibal Lecter.”

Read more zingers here.

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.