On a dirt road below the shrub-dotted hills of Arizona, Donald Trump used a stretch of wall and a pile of steel beams to draw a visual contrast between his approach to securing the border and that of his Democratic opponent, Vice President Kamala Harris.

Trump brought along grieving mothers, the sheriff of Cochise County and the head of the Border Patrol union to echo his tough-on-border security message at Thursday’s visit, which was themed “Make America Safe Again.”

“To my right is what we call Trump wall. This was wall that was built under President Trump,” said Paul Perez, the president of the Border Patrol union. “To my left, we have what we call Kamala wall. It’s just sitting there doing nothing, lying down.”

The Biden administration did not immediately respond to a request for comment on the wall construction.

The visit was the fourth in a series of events held in battleground states this week to try to draw the focus away from Democrats’ celebration of Harris’ presidential nomination in Chicago. Speakers at the convention on Wednesday night accused Trump of using the border to stir up his base by demonizing immigrants.

Joining Thursday’s border visit were the mothers of children who were killed during the Biden administration in cases where the suspects are immigrants in the country illegally. Trump frequently highlights attacks involving immigrants to fuel concerns about the Biden administration policies, though some studies have found that people living in the U.S. illegally are less likely than native-born Americans to have been arrested for violent, drug and property crimes.

“I just really, really, really want everybody to please take into consideration how important border control is because we’re losing very innocent people to heinous crimes,” said Alexis Nungaray, the mother of 12-year-old Jocelyn Nungaray, who was strangled to death in Houston in June.

At the Arizona event, snipers stood nearby at an elevated position, their eyes and weapons pointed toward Mexico, a day after Trump held his first outdoor rally since an assassination attempt last month. Security forces were also visible on the Mexican side of the border, including several men with rifles and tactical gear. Others wore uniforms identifying them as members of the Mexican state police.

“What Biden and Kamala have done to the families here with me and so many others, thousands and thousands of others, not only killed, but also really badly hurt, badly hurt to a point where they’ll never lead a normal life again. It’s shameful, and it’s evil,” Trump said.

In his tour of battleground states this week, Trump has traveled to Pennsylvania, Michigan and North Carolina and will hold events in Las Vegas and the Phoenix suburb of Glendale on Friday. His running mate, Sen. JD Vance of Ohio, spoke at the same location near the border a few weeks ago.

In the first four months of 2024, Border Patrol recorded more than 250,000 migrant apprehensions in the Tucson sector, which includes Cochise County. That was the most of any region patrolled by the agency, according to government statistics. 

But in recent months, the number of illegal crossings along the U.S.-Mexico border have fallen to the lowest level in years, according to Customs and Border Protection data obtained by CBS News, following President Biden’s order curtailing asylum and action by Mexico to stop migrants heading north.

Elected Democratic officials argued Wednesday night at the convention in Chicago that their party is the one offering real leadership on border issues.

Rep. Pete Aguilar of California, the chair of the Democratic Caucus, said Americans don’t have to make a choice between “a secure border and building an America for all.” 

“Under Harris, we can and will do both,” he said.

“When it comes to the border, hear me when I say, ‘You know nothing, Donald Trump,'” said Rep. Veronica Escobar, who represents the border city of El Paso, Texas. “He and his Republican imitators see the border and immigration as a political opportunity to exploit instead of an issue to address.”

Sen. Chris Murphy, a Connecticut Democrat, spoke after a video played showing Republican opposition to a bipartisan border deal earlier this year. Murphy was the top Democrat negotiating the proposal with conservative senators and said the bill would have had unanimous support if it weren’t for Trump.

Trump was asked about the deal, and he called it “weak” and “ineffective,” adding a bill was not needed for President Biden to take action.

“He didn’t need a bill. He knows that,” he said. “You know I didn’t have a bill. I said ‘close the border.'”

contributed to this report.