Protect your vote: In South Texas, the myth of non-citizen voting is taking center stage

This story is part of ABC News' month-long “Protecting Your Vote” series, profiling people across the country working to ensure the integrity of the electoral process.

Cecilia Castellano woke up in the early hours of August 20 to the sound of her doorbell. The South Texas sky was still dark outside her Atascosa County home, but when she emerged from her bedroom, her curlers were in place and a robe was draped over her shoulders – a slight cut through her foyer.

Two voices on the other side of her front door announced, “Police.”

“I came forward and actually looked through the window … and they shone a flashlight in my window,” Castellano recalled in an interview with ABC News' Mireya Villarreal. “They said, 'Ma'am, we have a search warrant.' I said, 'A search warrant for what?' And they say, 'Can we come in?'”

Officers presented Castellano with the search warrant, then confiscated her phone and asked her to write down the PIN, she said.

They were looking for evidence of so-called “vote harvesting,” an opaque provision of a 2021 voter integrity bill championed by the state's Republican governor, Greg Abbott, and enforced by his controversial attorney general, Ken Paxton.

Both men have cast the law, widely known as SB 1, as a protection against non-citizens voting – an extremely rare occurrence that is already prohibited under state and federal law. But Castellano, a Democratic candidate for a seat in the Texas State House, calls it voter intimidation.

“All I’ve done — everything my team has done — is go out and knock on doors,” Castellano said. “That’s why I was surprised. And to this day I go from being scared, to being angry, to thinking they violated my civil rights – they really tried to intimidate me.”

Castellano, a third-generation Mexican American, grandmother and business owner, launched her long-term bid for public office without expecting to attract much attention. But after August 20, her campaign became a flashpoint in the national debate over voting rights for non-citizens.

Castellano was among several prominent Latinos in Texas targeted in connection with Paxton's voter fraud investigation, which he said was sparked by “ample evidence” of voter fraud. According to Paxton's statement in August, a district attorney outside San Antonio referred allegations of “election fraud and vote harvesting” to the attorney general's office in 2022.

No charges were filed in the case.

“Why do they come to predominantly Latino areas?” Villarreal asked Castellano.

“Because they’re trying to intimidate Latinos,” Castellano replied.

Republicans, following former President Donald Trump's lead in claiming without evidence that undocumented immigrants could tip the scales in Democrats' favor in November, increasingly promoted the debunked narrative as the centerpiece of their voter canvassing in the months leading up to Election Day.

“Our elections are bad,” Trump said at the ABC News presidential debate in September. “And a lot of these illegal immigrants coming in are trying to get them to vote. They don't even know English, they practically don't even know what country they are in, and these people are trying to get them to vote and that's why they're allowing them to come to our country.”

House Speaker Mike Johnson, a Republican, recently tried unsuccessfully to pass a bill that would have required voters to prove their U.S. citizenship through documents — rather than certifying it under penalty of perjury, as current laws require – and argued in May that “We all know intuitively that many illegals vote in federal elections.”

But critics and election experts say that's simply not true, and they accuse Trump and his allies of making unsubstantiated and disingenuous claims about non-citizen voting in order to make it harder for eligible voters to register and vote. The libertarian Cato Institute called claims of widespread non-citizen voting an “alarmist theory,” and Pennsylvania's Republican elections director recently acknowledged that he “found this to be very, very, very rare.”

The Brennan Center for Justice, a nonpartisan think tank, found that less than 0.0001% of votes cast in the 2016 election were cast by suspected non-citizens.

“Noncitizen voting is a vanishingly rare phenomenon,” said Sean Morales-Doyle, a voting rights expert at the Brennan Center. “It is a criminal offense for a non-citizen to either register to participate in state and federal elections or to vote. Consequences include prison time, heavy fines and deportation.”

“It's just mind-boggling to think that someone who has decided to move to the United States with his family and try to build a life here is going to risk all of that – his freedom and his presence in the United States.” – to cast a vote in an election,” he said.

Still, leaders in a handful of Republican-led states have threatened to hold large-scale non-citizen elections to justify mass purges from their voter rolls, including in Tennessee, Alabama, Ohio and Texas — where Gov. Abbott has bragged about it since the passage of SB 1 In 2021, more than a million names were removed from the lists.

In Virginia, Republican Gov. Glenn Youngkin said he removed more than 6,000 people suspected of being non-citizens from the state's voter rolls – but a Washington Post investigation found not a single example of non-citizen voting during his time in office . And on Friday, the Justice Department sued Virginia for allegedly violating federal rules that prohibit states from removing voters from voter rolls within 90 days of an election. Youngkin called the lawsuit a “politically motivated action” aimed at “disrupting our elections.”

As the national debate over voting non-citizens rages on, Castellano has vowed to continue her campaign. During a recent afternoon in Jourdanton, Texas, as there was a knock on the door and a group of reporters chasing her, two police cruisers approached Castellano.

“Actually, I am the candidate for state representative for House District 80,” Castellano told the police officers, explaining that the cameras following them were reporters following her campaign.

“I look forward to winning your vote — the men in blue, the women in blue,” she told officials.