LAS VEGAS — For years, Sandra Diaz and Victorina Morales were undocumented and largely invisible employees of Donald Trump, domestics who laid out his golf clothes, served his meals and scrubbed his toilets, even as he took aim at illegal immigrants and Hispanics on the way to becoming president.

On Wednesday, the women held themselves up as symbols of what they called Trump’s hypocritical immigration policies as they received a standing ovation from Local 226, a culinary workers union that hosted three Democratic presidential candidates this week.

A short time after Morales and Diaz denounced their former employer Wednesday, they got a hug from one of Trump's chief opponents, former vice president Joe Biden, who was making his pitch to the largely Latino gathering of union workers.

“I’m going to tell you who is Mr. Trump,” Diaz told the crowd. “How he’s a big liar. . . . He still lies about immigrants. He says we are bad people. And I will stand here and say he lies, because we are good workers and good people.”

A short time later, Morales showed the crowd a photocopy of a certificate she had received from the White House Communications Agency for her service.

“He talked about immigrants, saying they’re thieves, they’re rapists,” she said through an interpreter. “But I am here showing my face saying we’re not who he says we are. We are hard workers, and here’s proof.”

For the women, it was the first major venture into political advocacy, as they sought to highlight an apparent dissonance between Trump’s message on illegal immigration and the dependence of his company, and his family, on undocumented immigrants. The women who once served Trump’s family are now calling for his ouster.

Diaz, 47, is an immigrant from Costa Rica who spent years as a housekeeper for Trump’s private villa at his golf club in Bedminster, N.J., before leaving in 2014. Morales, a 47-year-old from Guatemala, worked with Diaz and then succeeded her as Trump’s housekeeper.

Their jobs brought them close to Trump and his family. The two women ironed Trump’s clothes and replenished his supplies of Tic Tac breath mints and his rust-colored face makeup. They watched Trump’s interactions with his family and his in-laws, first lady Melania Trump’s parents, who also spent long periods at Bedminster.

Their work required them to be invisible, in two senses. In the villas, they left no trace, coming and going without leaving even a hint of perfume in the air. They also sought to be invisible in a legal sense, because both women were undocumented and had been hired by Trump after submitting false immigration documents. They both believe managers at the Trump club were aware of their undocumented status.

Late last year, angered by Trump’s attacks on undocumented immigrants, both outed themselves as undocumented in media interviews, beginning with the New York Times.

“How can you know something so big, how someone — who goes on national television and says something — and you know it’s not true?” Diaz told The Washington Post recently. “Whether it’s the president or not, you have the responsibility to say no, to pass through this barrier of fear and say no.”

At the time, Morales was still working for Trump. She quit. Diaz was working for a member of Trump’s golf club as a private housekeeper. She says she was fired; her former employer did not respond to requests for comment.

The women said that even while Trump was denouncing undocumented workers in public, he was relying on them in private — as housekeepers, groundskeepers, waiters and stonemasons. In all, The Washington Post has spoken to 48 current or former employees at the Trump Organization who were undocumented. They worked at 11 different Trump properties.

The Trump Organization has blamed the workers for deceiving them, and has now begun using the federal E-Verify system to screen all new hires. It has fired at least two dozen other undocumented employees, saying that a new internal audit showed their documents — often submitted to the Trump Organization years earlier — were fake.

So far, none of the 48 are known to have been deported. The Trump Organization is facing investigations of its practices by state attorneys general in New York and New Jersey, but it is unclear if it will face any legal repercussions.

Organizers of Wednesday’s union event said Morales had “gotten status” and found a job at a unionized hotel making $32 an hour. But she and Diaz spent the first part of this week sharing a stage with presidential aspirants.

Biden, Sen. Elizabeth Warren (D-Mass.) and Sen. Bernie Sanders (I-Vt.) all spoke this week to Local 226 and Local 165, a bartenders union. Their speeches touched on the contentious intersection of race, class and immigration in Nevada, where Latinos make up 29 percent of the population. The candidates made their pitches to standing-room-only crowds of the 60,000-member union, who are the backbone of the city’s hospitality industry.

On Wednesday, Biden, who has had town halls interrupted by immigration protesters in the past, highlighted his recently released immigration policy. In his first 100 days as president, he said, he would erase many of Trump’s immigration policies. He also outlined a road map to citizenship for 11 million undocumented people and proposed raising the country’s refu­gee cap.

Biden told attendees about the struggles of his Irish Catholic ancestors who tried to make a better life in America, saying the immigrants in the room did not deserve the animus directed at them by Trump.

“You all don't leave because you want to leave,” he said, referring to the decision to depart from one’s native country. “You leave because you don’t have a choice.”

A Biden administration, the former vice president said, would be more humane, and the immigrants targeted for deportation would be those who had committed major crimes.

“Nobody’s going to be standing outside Mass as you come out to arrest somebody because you showed up at church,” he said. Immigration and Customs Enforcement “is not going to be standing in front of schools.”

Fahrenthold reported from Washington. Joshua Partlow contributed to this report.