Flanked by family members whose loved ones were killed by suspects who illegally entered the country, former President Donald Trump claimed, without evidence, that Vice President Kamala Harris will allow 100 million people to cross into the country illegally if elected.

Trump's visit to Arizona, his latest counterprogramming event to the Democratic National Convention, comes as Democrats have taken to the stage in Chicago to condemn the ex-president's lobbying to kill a bipartisan bill aimed at securing the U.S.-Mexico border.

“She’s a radical left person who really wants to have an open border. She’ll never close the border,” Trump said at an event where portions of unconstructed border wall lay on their side. On his first day in office, President Joe Biden issued an executive order to stop construction of the border wall that was a centerpiece of Trump’s term in office.

“We have a Marxist that’s running. This country is not ready for a Marxist president,” Trump charged. “She will never build the wall. She doesn’t want to build the wall. If she changes her mind, it’s only because she wants to get elected. We need strong borders and strong elections, and we have nether.”

Repeatedly referring to Harris as "Comrade Kamala," a "Marxist" and the country’s "border czar" -- a false line of attack to try and blame Harris for the Biden administration's border policies -- he also accused the media of failing to cover “the bad things that are going on in this country,” including the “fights and shootings” endured by police, local law enforcement and Immigration and Customs Enforcement officials.

In March 2021, Biden assigned Harris with leading the administration’s efforts to address the root causes of what propels people in Guatemala, El Salvador and Honduras to attempt to migrate to the U.S. Border security is the responsibility of Homeland Security Secretary Alejandro Mayorkas. The White House has never used the term “border czar” to describe Harris’ role.

Trump charged that Harris, along with her running mate Minnesota Gov. Tim Walz, has “unleashed a deadly plague of migrant crime on our country by not doing their job.”

He also said illegal “aliens” are shattering Americans’ lives and also taking jobs from Black and Hispanic workers in the U.S. -- Trump has drawn some criticism from Democrats for such comments about "Black jobs" and "Hispanic jobs" -- adding that union jobs were also on the line. He also repeated claims that other countries are sending those who are mentally ill and with criminal backgrounds into the country.

“The level of criminality is unbelievable. It’s an onslaught of violence at a level that nobody’s ever seen before. For nearly four years as border czar, Comrade Kamala has seen a nation-wrecking invasion” of at least 20 million people, “including millions and millions of unvetted fighting-age men from over 158 countries,” he said, before citing statistics about increasing levels of violent crime and accusing the Federal Bureau of Investigation of inaccurately reporting the numbers.

The most recent data from the Federal Bureau of Investigation show murder decreased 26.4%, rape decreased 25.7%, aggravated assault fell 12.5% and robbery decreased 17.8% in the first quarter of 2024 compared with a year earlier. Many cities across the U.S. are seeing sharp declines in violent crime. 

And while the number of illegal border crossings has surged in recent years, those totals have taken a steep drop in recent months in the wake of executive action from President Joe Biden in June to limit asylum claims when the U.S.-Mexico border gets overwhelmed. The number of illegal crossings fell to a four-year low last month; Border Patrol reported 56,408 encounters between ports of entry along the U.S.-Mexico border in July, the lowest montly total since September 2020. It also represents a 32% drop from the month prior.

During a speech that lasted more than an hour, Trump let two women share stories of their children being killed by suspects who are believed to have entered the country illegally. Another woman from San Francisco recounted having her skull being fractured by two men in the country illegally.

If reelected, Trump has said he will launch the largest deportation effort in U.S. history and impose the death penalty for anyone found guilty of sex trafficking, major drug dealing or killing a police officer, sheriff, border patrol agent, Immigration and Customs Enforcement agent or law enforcement official.

Pledging to make America safe again, he said, “Republican, Democrat, it doesn’t matter. We have to have strong protection in our country or our country will wither away and die.”

Trump's running mate, Ohio Sen. JD Vance, held a separate event in Georgia on Thursday aimed at hammering Harris on immigration. 

Speakers at the Democratic convention, meanwhile, have hammered Trump on the issue, including Connecticut Sen. Chris Murphy, one of the three lawmakers who negotiated a bipartisan bill aimed at bolstering border security.

Trump urged GOP lawmakers to reject the deal after it was reached, reportedly because he wanted to campaign on unresolved border issues. Republicans in Congress, however, insisted the agreement made too many concessions to Democrats.

“Donald Trump's allies weren't just in the room,” Murphy said. “They helped us write the whole bill. It was a bipartisan bill. It was a tough bill.”

Murphy claimed one Republican told him the legislation would have passed with near unanimous support if Trump had not intervened.

“Trump killed that bill, and he did it because he knew that if we fixed the border, he'd lose his ability to divide us, his ability to fan the flames of fear about people who come from different places,” Murphy said. “ … Hate and division — that's Trump's oxygen.”

Murphy said that while Trump says “a safe nation can’t be an immigrant nation,” Harris “knows that we can be a nation of proud immigrants and a nation of strong immigration laws.”

Spectrum News' Ryan Chatelain contributed to this report.