CHARLOTTE, N.C. - Former President Trump repeatedly took aim at Vice President Kamala Harris - his new opponent in the 2024 presidential election, as he returned to the campaign trail Wednesday with a stop in the crucial swing state of North Carolina.

"Now we have a new victim to defeat – lying Kamala Harris," the Republican presidential nominee charged at a large rally at an arena in Charlotte, the state's largest city.

The Republican presidential nominee is facing a dramatically altered 2024 race in his first rally since President Biden's blockbuster announcement Sunday that he was suspending his re-election bid and endorsing Harris to succeed him as the Democratic Party's standard-bearer.

The president's immediate backing of Harris ignited a surge of endorsements of Harris by Democratic governors, senators, House members and other party leaders. By Monday night, the vice president announced she'd locked up her party's nomination by landing the backing of a majority of the nearly 4,000 delegates to next month's Democratic National Convention. She also hauled in a staggering $100 million in the first 36 hours following Biden's announcement.

IT'S A MARGIN OF ERROR RACE BETWEEN TRUMP AND HARRIS 

Kamala Harris

Vice President Kamala Harris, the Democratic presidential candidate, speaks at West Allis Central High School during her first campaign rally in Milwaukee July 23, 2024. (Kamil Krzaczynski/AFP via Getty Images)

And new polls conducted after Biden bowed out indicate a margin-of-error race between Harris and Trump.

The former president, pointing to the assassination attempt against him a week and a half ago, said "I was supposed to be nice. Something happened to me when I got shot. I got nice."

"If you don’t mind, I’m not going to be nice," Trump said to cheers from the crowd.

Trump quickly took aim at Harris, claiming she was "incompetent" and the "worst vice president in American history."

The former president also repeatedly worked to portray the vice president as a "radical left lunatic."

Trump argued that Harris is "more liberal than [Sen.] Bernie Sanders. Can you believe it."

Pointing to Biden's stunning announcement that came amid a growing chorus of calls from within the Democratic Party for him to drop out in the wake of his disastrous debate performance last month against Trump, the former president claimed "he quit because he was losing so badly in the polls."

Trump argued that the pressure by Democrats on Biden to suspend his re-election bid was "an undemocratic move" and charged that "these are nasty people, the Democrats."

Former President Donald Trump criticizes Vice President Kamala Harris at a rally in North Carolina

Former President Donald Trump, the GOP presidential nominee, headlines a rally in Charlotte, North Carolina on July  24, 2024  (Fox News - Paul Steinhauser)

Ahead of the rally, Republican National Committee Chair Michael Whatley said even though Trump's now facing a new opponent at the top of the Democrats' ticket, the GOP's strategy "does not change … at all."

"We have been running our race, and we are going to continue to run our race," Whatley, a former North Carolina GOP chair whom Trump installed as RNC chair in March after clinching the Republican nomination, emphasized in a Fox News interview.

WHAT'S NEXT FOR HARRIS NOW THAT SHE'S SEEMINGLY LOCKED UP THE DEMOCRATIC NOMINATION?

Whatley, speaking at the rally site at Charlotte's Bojangles Coliseum, noted that Trump and the RNC will relentlessly tie Harris to Biden's polices on border security, fighting inflation, crime and other top issues in the 2024 election.

"The Democrats not only have a messenger problem, they have a message problem. And Kamala Harris is doubling down on every single one of Joe Biden's failed policies. It's the Biden-Harris administration, the Biden-Harris campaign. And she is picking up that mantle," Whatley argued.

The RNC chair emphasized Trump "has absolutely united the Republican Party in a way we haven't had in generations. Now it's time to unite the country around that vision of making America great again."

Donald Trump holds his first campaign rally since Vice President Kamala Harris replaced President Biden atop the Democratic Party's 2024 ticket

The crowd inside the Bojangles Coliseum ahead of former President Trump's appearance at a rally in Charlotte, N.C., July 24, 2024 (Fox News/Paul Steinhauser)

Trump narrowly won North Carolina in his 2020 election defeat to Biden, and Democrats see an opportunity to flip the state this November.

The trip by Trump to North Carolina is his second in two months. The last time Trump was in North Carolina, he was watching NASCAR in Concord over Memorial Day weekend. 

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The state is one of seven crucial battlegrounds that decided the 2020 contest and is likely to once again heavily influence the outcome of the 2024 presidential election.

"We continue to focus on the Blue Wall states of Michigan, Wisconsin, and Pennsylvania — and the Sun Belt states of North Carolina, Georgia, Arizona and Nevada, where the Vice President’s advantages with young voters, Black voters, and Latino voters will be important to our multiple pathways to 270 electoral votes," a memo from the Harris campaign said hours before Trump arrived in North Carolina.

Trump in Grand Rapids

Former President Trump, the Republican presidential candidate, speaks at a campaign rally July 20, 2024, in Grand Rapids, Mich. (AP Photo/Evan Vucci)

Whatley said Trump, in his speech in North Carolina, needs to "continue his conversation with every American family, talking to every single American voter about his vision for a better America. He is going to be the one who is going to restore our southern border, restore our economy, restore our standing in the world and really be the one around that vision."

But expect Trump to also take aim at Harris. He's amped up his verbal attacks on the vice president since Sunday in posts on this Truth Social platform.

Among other things, the former president called her "Dumb as a Rock" and "a totally failed and insignificant Vice President."

Harris is also turning up the volume. In a tease of her argument against Trump, Harris is pointing to her law enforcement resume as she spotlights Trump's legal controversies.

"As many of you know, before I was elected as vice president, before I was elected as United States senator, I was the elected attorney general of California. Before that, I was a courtroom prosecutor. In those roles, I took on perpetrators of all kinds," Harris said Monday in a line she repeated the next day.

"Predators who abused women, fraudsters who ripped off consumers, cheaters who broke the rules for their own gain. So, hear me when I say I know Donald Trump’s type," she emphasized as she pointed to Trump's multiple lawsuits and criminal cases, many of which are ongoing.

Get the latest updates from the 2024 campaign trail, exclusive interviews and more at our Fox News Digital election hub.

Fox News' Jennifer Johnson contributed to this story.