DOUGLAS, Ariz. — With a forecast high temperature near triple digits in late September, Vice President Kamala Harris on Friday is diving into one of the most heated issues of the presidential campaign: immigration.

Harris made her first trip to the southern U.S. border in more than three years. It’s her first visit since President Joe Biden dropped out of the race and she took over at the top of the ticket.

“We do have a broken immigration system,” Harris said Wednesday in an interview with MSNBC. “And it needs to be fixed.”

Harris will call for tougher security measures, including new fentanyl detection machines and more Border Patrol agents, a senior campaign aide told NBC News. The aide said she also plans to press the Chinese government to do more crack down on companies that make the precursor chemicals used to make fentanyl. Her team is also out with a new ad touting her record as California’s attorney general and highlighting that she prosecuted transnational gangs and drug traffickers.

Harris will also propose on Friday that the U.S. tighten asylum restrictions, according to the aide.

She will propose going further than Biden’s executive action this year, which said that if border encounters rise above a 7-day average of 1,500, then migrants crossing the border illegally cannot apply for asylum. Harris intends to require a lower average of illegal border crossings for the restriction to kick in, according to a senior campaign official. The official also said that Harris would implement stronger emergency authorities.

It’s a remarkable attempt at rebranding for a vice president in an administration that has had a record 10 million illegal border crossings since Biden took office. (Crossings have dropped dramatically since he issued the executive action this year to tighten asylum restrictions.)

In discussing immigration, Harris has increasingly attacked Trump over his efforts to kill a bipartisan border funding deal this year.

“He killed a bill that would have actually been a solution because he wants to run on a problem,” Harris said in her MSNBC interview.

House Speaker Mike Johnson, R-La., argued the Senate-negotiated bill didn’t go far enough, while Republicans have tried to label Harris as the administration’s “border czar.” Her aides have insisted that her purview was much narrower and that she was tasked with looking into the root causes of migration in the “Northern Triangle” countries of El Salvador, Guatemala and Honduras.

“She keeps talking about how she supposedly wants to fix the border,” Trump said Thursday at a news conference at Trump Tower. “Why didn’t she fix it almost four years ago?”

An NBC News poll conducted this month found that 54% of registered voters thought Trump would better handle securing the border and controlling immigration, compared with 33% who said the same of Harris. 

The poll also indicated that 57% of registered voters thought Harris would be better at treating immigrants humanely and protecting immigrant rights, with 29% saying Trump would be better. 

“They’re infecting our country,” Trump said Thursday. “They’re destroying our country.”

The heated debate over immigration is especially critical in battleground Arizona, where rancher John Ladd’s family has owned 16,000 acres in Cochise County for more than a century.

“Trump had it figured out,” he said in an interview, adding that the number of border apprehensions on his property peaked at around 150 a day during the Biden administration but was much lower under Trump.

“They come through me every day,” he said. “But they go live with you.” 

Miles of border wall were constructed on his property — and had to be repaired multiple times early this year after smugglers cut a hole in it, he said. He’s skeptical of Harris’ tougher talk on immigration.

“That’s baloney,” he said. “That’s an absolute lie. She doesn’t care about the border. She wants it open. So I don’t believe a word she says.” 

Danya Acosta, a City Council member and former sheriff’s deputy in nearby Douglas, said Harris has won her over, though she has been frustrated by the heated rhetoric over immigration on the campaign trail.

“A lot of us here in the border communities are a little tired of the polarization that has occurred when it comes to that topic,” she said.

She said she voted for Trump in 2016 and Biden in 2020 — but that she had been disappointed by what she considered to be Biden’s lax border policies. The failure of the bipartisan border bill in the Republican-controlled House changed her mind. 

“That really swayed my vote in that this isn’t about a problem — this is about political gain,” she said. “And that’s really sad that people are being used as pawns for political reasons.”