Trump's campaign is targeting Harris in its biggest television ad buy since at least January, reserving eight-figure dollar worth of airtime in six key battleground states, according to ad tracking firm AdImpact.

The 30-second ad zeroes in on the rhetoric that Harris "failed" in her role handling immigration issues in President Biden's administration, calling her "weak" and "dangerously liberal."

"This is America's border czar, and she's failed us. Under Harris, over ten million illegally here, a quarter of a million Americans dead from fentanyl, brutal migrant crimes, and ISIS now here," a narrator in the ad says, followed by an interview clip of Harris appearing to admit she hasn't visited the border.

Harris was assigned to address the root causes of migration in Central and South America. She made one visit to the southern border operations in June 2021.

The Harris campaign hit back that Trump was responsible for "killing the toughest border deal in decades" and accused him of misrepresenting her record.

"As a former district attorney, attorney general, and now vice president, Kamala Harris has spent her career taking on and prosecuting violent criminals and making our communities safer. She'll do the same as president," said Harris campaign spokesperson Ammar Moussa.

-ABC News' Soorin Kim and Gabriella Abdul-Hakim

Appearing on Fox News "The Ingraham Angle" on Monday night, Trump attempted to clean up his vice presidential pick's previous comments about "childless cat ladies," but didn't really address the comments.

Instead, he rambled about how Vance is pro-family.

"He made a statement having to do with families. That doesn't mean that people that aren't a member of a big and beautiful family with 400 children around and everything else, it doesn't mean that a person doesn't have, he's not against anything, but he loves family. It's very important to him. He grew up in a very interesting family situation, and he feels family is good, and I don't think there's anything wrong in saying that," Trump said downplaying Vance's comments.

Trump also attacked Democrats, saying they spun Vance's words out of context. He then quipped that "in many cases" people without a family are better off than those with one.

"You don't meet the right person, or you don't meet any person, but you're just as good, in many cases, a lot better than a person that's in a family situation," Trump said.

-ABC News' Lalee Ibssa, Soorin Kim and Kelsey Walsh

The Democratic National Committee held a "Women for Harris" call on Monday night.

Over the course of two and a half hours, viewers heard from Chelsea Clinton, California Sen. Laphonza Butler, Michigan Gov. Gretchen Whitmer, Gloria Steinem, Ana Navarro and leaders of organizations like Emily’s List and Mom's Demand Action.

Clinton lamented her mother’s loss in 2016 but told viewers that defeating the former president is even more important than it was in 2016 because Americans now have a "record" of things to hold him accountable for.

"My mom put a few more cracks in that glass ceiling. And Vice President Harris is going to obliterate that glass ceiling," Clinton said.

The call included a host of organizations who support Harris, including Black women who held the first iteration of these pop up fundraising calls with the group Win with Black Women. Glynda Carr, founder of Higher Heights PAC, which supports Black women leadership, told attendees what made this call uniquely important was the realization that women from all walks of life are “stronger together.”

Another "Women for Harris" call is planned for Tuesday night.

-ABC News' Gabriella Abdul-Hakim, Fritz Farrow and Will McDuffie

Vice President Kamala Harris rolled out an aggressive $50 million, three-week advertising blitz for the first ad of her presidential campaign on Tuesday, in which she introduces herself to voters, highlights her career and takes hits at former President Donald Trump.

"The one thing Kamala Harris has always been: fearless," a narrator says at the start of the minute-long ad, as pictures of Harris over the years -- from a toddler to college graduate to vice president -- flash on screen.

"As a prosecutor, she put murderers and abusers behind bars," the narrator continued. "As California's attorney general, she went after the big banks and won $20 billion for homeowners. And as vice president, she took on the big drug companies to cap the cost of insulin for seniors. Because Kamala Harris has always known who she represents."

The spot then leads into laying out Harris' vision and attacking Trump, using footage from her first rally of the campaign last week in a high school gym just outside Milwaukee, Wisconsin.

"We believe in a future where every person has the opportunity not just to get by, but to get ahead. Where every senior can retire with dignity," Harris said in the footage from the rally. "But Donald Trump wants to take our country backward, to give tax breaks to billionaires and big corporations and end the Affordable Care Act."

"But we are not going back," she added.

Harris campaign chair, Jen O'Malley Dillon, said in a statement that because of Harris' prosecutorial, congressional and vice-presidential experience, the vice president is "uniquely suited to take on Donald Trump, a convicted felon who has spent his entire life ripping off working people, tearing away our rights, and fighting for himself."

-ABC News' Gabriella Abdul-Hakim, Fritz Farrow, Isabella Murray and Will McDuffie