WATERLOO, Iowa (AP) — Former President Donald Trump on Tuesday defended his comments about migrants crossing the southern border "poisoning the blood" of America, and he reinforced the message while denying any similarities to fascist writings others had noted.

"I never read 'Mein Kampf,'" Trump said at a campaign rally in Waterloo, Iowa, referencing Adolf Hitler's fascist manifesto.

Immigrants in the U.S. illegally, Trump said Tuesday, are "destroying the blood of our country, they're destroying the fabric of our country."

In the speech to more than 1,000 supporters from a podium flanked by Christmas trees in red MAGA hats, Trump responded to mounting criticism about his anti-immigrant "blood" purity rhetoric over the weekend. Several politicians and extremism experts have noted his language echoed writings from Hitler about the "purity" of Aryan blood, which underpinned Nazi Germany's systematic murder of millions of Jews and other "undesirables" before and during World War II.

As illegal border crossings surge, topping 10,000 some days in December, Trump continued to blast Biden for allowing migrants to "pour into our country." He alleged, without offering evidence, that they bring crime and potentially disease with them.

"They come from Africa, they come from Asia, they come from South America," he said, lamenting what he said was a "border catastrophe."

Trump made no mention of the Colorado Supreme Court's decision Tuesday to disqualify him from the state's ballot under the U.S. Constitution's insurrection clause, though his campaign blasted out a fundraising email about it during his speech.

The former president has long used inflammatory language about immigrants coming to the U.S., dating back to his campaign launch in 2015, when he said immigrants from Mexico are "bringing drugs, they're bringing crime, they're rapists."

But Trump has espoused increasingly authoritarian messages in his third campaign, vowing to renew and add to his effort to bar citizens from certain Muslim-majority countries, and to expand " ideological screening " for people immigrating to the U.S. He said he would be a dictator on "day one" only, in order to close the border and increase drilling.

In Waterloo on Tuesday, Trump's supporters in the crowd said his border policies were effective and necessary, even if he doesn't always say the right thing.

"I don't know if he says the right words all of the time," said 63-year-old Marylee Geist, adding that just because "you're not fortunate enough to be born in this country," doesn't mean "you don't get to come here."

"But it should all be done legally," she added.

It's about the volume of border crossings and national security, said her husband, John Geist, 68.

"America is the land of opportunity, however, the influx — it needs to be kept to a certain level," he said. "The amount of undocumented immigrants that come through and you don't know what you're getting, things aren't regulated properly."

Alex Litterer and her dad, Tom, of Charles City said they were concerned about migrants crossing the southern border, especially because the U.S. doesn't have the resources to support that influx. But the 22-year-old said she didn't agree with Trump's comments, adding that immigrants who come to the country legally contribute to the country's character and bring different perspectives.

Polling shows most Americans agree, with two-thirds saying the country's diverse population makes the U.S. stronger.

But Trump's "blood" purity message might resonate with some voters.

About a third of Americans overall worry that more immigration is causing U.S.-born Americans to lose their economic, political and cultural influence, according to a late 2021 poll by The Associated Press-NORC Center for Public Affairs Research.

Jackie Malecek, 50, of Waterloo said she likes Trump for the reasons that many people don't — how outspoken he is and "that he's a little bit of a loose cannon." But she thought Trump saying immigrants are "poisoning the blood" took it a little too far.

"I'm very much for cutting off what's happening at the border now. There's too many people pouring in here right now, I watch it every single day," Malecek said. "But that wording is not what I would have chosen to say."

Malecek supports allowing legal immigration and accepting refugees, but she is concerned about the waves of migrants crossing the border who are not being vetted.

Sen. JD Vance, a Republican from Ohio, lashed out at a reporter asking about Trump's "poisoning the blood" comments, defending them as a reference to overdoses from fentanyl smuggled over the border.

"You just framed your question implicitly assuming that Donald Trump is talking about Adolf Hitler. It's absurd," Vance said. "It is obvious that he was talking about the very clear fact that the blood of Americans is being poisoned by a drug epidemic."

At a congressional hearing July 12, James Mandryck, a Customs and Border Protection deputy assistant commissioner, said 73% of fentanyl seizures at the border since the previous October were smuggling attempts carried out by U.S. citizens, with the rest being done by Mexican citizens.

Extremism experts say Trump's rhetoric resembles the language that white supremacist shooters have used to justify mass killings.

Jon Lewis, a research fellow at George Washington University's Program on Extremism, pointed to the 2018 Pittsburgh synagogue shooter and the 2019 El Paso Walmart shooter, who he said used similar language in writings before their attacks.

"Call it what it is," said Lewis. "This is fascism. This is white supremacy. This is dehumanizing language that would not be out of place in a white supremacist Signal or Telegram chat."

Asked about Trump's "poisoning the blood" comments, Senate Republican leader Mitch McConnell replied with a quip about his own wife, an immigrant, who was an appointee in Trump's administration.

"Well, it strikes me that didn't bother him when he appointed Elaine Chao Secretary of Transportation," McConnell said.

Trump currently leads other candidates, by far, in polls of likely Republican voters in Iowa and nationwide. Trump's campaign is hoping for a knockout performance in the caucuses that will deny his rivals momentum and allow him to quickly lock up the nomination. Florida Gov. Ron DeSantis has staked his campaign on Iowa, raising expectations for him there.

"I will not guarantee it," Trump said of winning Iowa next month, "but I pretty much guarantee it."

___

This story has been corrected to change a reference to this year's Texas mall shooting to the 2019 El Paso Walmart shooting.

___

Associated Press reporters Elliot Spagat in San Diego and Lisa Mascaro in Washington contributed to this report.