MILWAUKEE — Sen. Elizabeth Warren accused President Donald Trump of stirring “hate.” Julián Castro said the president had acted “like a dictator.” The Trump administration’s actions, warned Beto O’Rourke, threaten to “stain” the nation’s conscience.

The Democratic presidential candidates, gathered in Milwaukee on Thursday to address Latino voters, excoriated Trump’s immigration and deportation policies and channeled rising anxiety among a constituency that could be crucial in the 2020 primary race.

The appearances by Warren, Castro and O’Rourke, as well as by Sen. Bernie Sanders of Vermont and Rep. Tulsi Gabbard of Hawaii, were part of a multiday event, hosted by the League of United Latin American Citizens, or LULAC, which organizers said could draw 15,000 to 20,000 people to a convention center in this lakeside city.

“What we’re seeing with our community at this very moment in America’s history is a high level of fear,” said Sindy Benavides, the chief executive officer of LULAC. “And for many in our community, it’s really looking at the fact that who gets elected matters. Who sits at the local, at the state, at the national level, matters.”

Warren, Castro, O’Rourke and Sanders also participated in a forum Thursday night.

Immigration and Customs Enforcement is planning to conduct raids this weekend targeting thousands of members of families who are in the country illegally, according to current and former homeland security officials, a move O’Rourke, a former congressman from Texas, said “not only will remain a stain on our conscience if we allow this to continue but will also make us less safe as a country.”

The humanitarian crisis continues at the southern border, as migrant children who were separated from their parents have confronted illness, unsanitary conditions and overcrowding in detention centers.

And for much of Thursday there was widespread concern at the conference that Trump would insist on pursuing the addition of a question about citizenship to the 2020 census. Such an action would have the potential to suppress immigrant participation, leading to an undercount of about 6.5 million people, according to government experts. That could reduce Democratic representation in Congress and direct federal resources away from communities where migrants live.

Late Thursday afternoon, Trump dropped that effort and told the government to cull data on citizenship from existing federal records.

“Wow, he’s going to follow the law,” Warren, of Massachusetts, remarked sarcastically when asked about Trump’s reversal on the issue. “This is not about trying to find out real information about citizenship and noncitizenship in America. This is just about trying to stir up some more hate, to try to get more people excited.”

Hours before, Warren released an immigration policy proposal, calling for a decriminalization of unlawful entry, expanded legal immigration, a “fair and achievable” pathway to citizenship and the end of private detention facilities, among other ideas, a vision she promoted at the presidential forum.

Many Latino activists worry the fears surrounding the census will keep some immigrants from participating regardless of the outcome of the legal fight.

“As it is, my people, my Latino people, don’t want to come out and answer the door,” Angie Barajas, who is active with a local LULAC chapter in El Paso, Texas, said Thursday afternoon.

At the gathering, which is slated to draw seven Democratic presidential candidates over the course of three days, frustration with the Trump administration was at a boiling point. The Democratic candidates who spoke in this city, which will host the Democratic National Convention next year, wasted no time drawing contrasts with Trump.

“This is more evidence of how erratic this president is,” said Castro, a former housing secretary, regarding the citizenship question. “He’s weak. This is more evidence of how erratic and weak he is.”

And Sanders said that Trump was “trying to divide this country up based on the color of our skin or where we came from.” (Sanders also said, in response to an audience member’s question, that he would support abolishing the Electoral College, a stronger stance on the matter than he has taken in the past.)

Michael Joyce, a spokesman for the Republican National Committee, said in response to the candidates’ remarks: “The Democrats’ message to illegal immigrants is clear: You can stay, you won’t be punished, and American taxpayers will pay for your health care. They’ve moved completely outside of the mainstream.”

On Thursday, Castro addressed a luncheon at LULAC, where he earned a standing ovation. Afterward he held a news conference where, unprompted, he criticized former Vice President Joe Biden for saying that he did not support plans to decriminalize unlawful border crossings.

“It is a mistake for Vice President Biden to take that position,” said Castro, who, like Biden, served in the Obama administration. “I’m disappointed that Vice President Biden is refusing to repeal a law that was sponsored and authored by a segregationist senator in the late 1920s that is the reason this administration can separate little children from their parents.”

Biden was not in attendance — he was in New York to give a foreign policy address and to attend fundraiser — but his wife, Jill Biden, addressed a session of the conference Thursday morning.

“As the fastest-growing demographic, your success is success for us all,” she said. “When we invest in Latinos, we all reap the rewards.” The Biden campaign declined to respond to Castro’s criticism.

Trump is expected in Milwaukee on Friday to visit an aerospace center and attend a fundraiser.

Addressing the president’s visit, Barajas, the El Paso activist, referenced his tossing paper towels to a crowd in Puerto Rico shortly after Hurricane Maria had devastated the island, an episode that still angers many Latinos.

“If I knew where he was coming on Friday — I have a box of paper towels,” she said. “See if he likes it.”

This article originally appeared in The New York Times.