On the same day Vice President Kamala Harris is set to give her formal acceptance speech at the Democratic National Convention on Thursday, former President Donald Trump focused on the topic he has criticized Harris for the most: immigration.

Trump spent the day on Thursday at the U.S.-Mexico border in southern Arizona after spending the week hopping from one battleground state to another, focusing on policy-centered speeches in states such as Michigan, Pennsylvania and North Carolina. Both Trump and running mate JD Vance are engaging in counterprogramming to the DNC, which is taking place in Chicago this week.

“As Kamala gives her convention speech tonight. She will not mention the victims,” he said, apparently referring to migrants in the country illegally accused of murder and other violent crimes. “She won’t even talk about them, although, now that she sees us, maybe she will. She will not say their names or express remorse to their families. Kamala say she wants to talk about the future. No, these people want to go back to the safe past. We’re going to have a future with open borders and all of the other problems.”

With Harris formally the Democratic candidate and set to face Trump, the former president has zeroed in on criticizing Harris’ immigration policies, putting the blame squarely on her for the situation at the border as he latches on to his inaccurate reference to her as the “border czar.”

The label stems from President Joe Biden assigning Harris to oversee and lead diplomatic talks with Northern Triangle countries to address the root cause of migration. Republicans quickly focused on the assignment, dubbing her the “border czar” — though technically Secretary of Homeland Security Alejandro Mayorkas is in charge of the border.

Harris has defended her work on the border, and her campaign has included in a tv ad that as president she would “hire thousands more border agents and crack down on fentanyl and human trafficking.”

After touring the border, Trump is set to deliver his remarks right by the border wall he backed with a long stretch of the structure as his backdrop.

It’s a throwback to his campaign promise from his very first presidential campaign to build a wall along the U.S.-Mexico border — and an emphasis on his current campaign’s promise to finish the wall. His administration implemented roughly 450 miles of barriers, much of which was just upgrading existing barriers.

Border security and immigration has continued to be one of Trump’s main campaign issues this election. The former president has repeatedly pushed anti-immigrant rhetoric on the campaign trail, claiming immigrants in the country illegally are “poisoning the blood of our country” and that they are taking away Americans’ jobs.

His disparaging comments on immigrants living in the country without authorization have ramped up in recent months. Trump has described migrants crossing the border as violent criminals by highlighting stories about crimes committed by them, despite crime statistics analysis suggesting that U.S. citizens commit crimes at higher rates than unauthorized immigrants.

“Relative to undocumented immigrants, U.S.-born citizens are over 2 times more likely to be arrested for violent crimes, 2.5 times more likely to be arrested for drug crimes, and over 4 times more likely to be arrested for property crimes,” according to a 2020 study in the Proceedings of the National Academy of Sciences.

On Wednesday, Trump suggested that there were migrants in the country illegally at his campaign event in Asheboro, North Carolina.

“We probably have a few here. Welcome, welcome, but we probably have a few here, and [Harris is] all for it,” Trump quipped as the crowd responded by chanting, “Build that wall.”

Throughout the week, Trump has attempted to stay on message on key themes of the economy, crime and safety, and national security as allies and supporters push for Trump to focus on his potential second term agenda rather than spewing personal attacks.

Throughout his speeches this week, Trump has been criticizing DNC speakers, taking specific aim at former President Barack Obama and former first lady Michelle Obama, calling Barack Obama’s tone “nasty.”

“Did you see Barack Hussein Obama last night? He was taking shots at your president. And so is Michelle. They always say, please stick to policy, don’t get personal. Yet they are getting personal all night long, these people. Do I still have to stick to policy?”

“I try and be nice to people, you know, but it’s a little tough when they get personal,” Trump lamented.