Bodyguards escorted Univison's Jorge Ramos out of Republican presidential candidate Donald Trump's news conference Aug. 25. After guards let the reporter back in, he went back and forth with Trump about his immigration plan. (MSNBC/Asya Akça, Radio Iowa)

This story has been updated.

DUBUQUE, Iowa — Two minutes into Donald Trump's news conference here Tuesday night came the question he tried to silence.

"Mr. Trump, I have a question," said Jorge Ramos, the top news anchor at Univision and one of the country's most recognizable Mexican-Americans, as he stood up in the front row of journalists.

"Excuse me," the Republican presidential front-runner told Ramos. "Sit down. You weren't called. Sit down."

Ramos, holding a piece of paper, calmly tried to ask Trump about his plan to combat illegal immigration. "I'm a reporter, an immigrant, a senior citizen," he said. "I have the right to ask a question."

Trump interrupted him. "Go back to Univision," he said. Then the billionaire businessman motioned to one of his bodyguards, who walked across the room and physically removed Ramos from the room.

Jorge Ramos was escorted out of a Donald Trump news conference on Tuesday after the presidental hopeful refused to recognize the Univision anchor's questions on immigration. (Asya Akça, Radio Iowa/Twitter)

Trump's dismissal of a major television news anchor lit up social media. Reporters asked Trump why he removed Ramos. At first, he accused Ramos of violating his news conference protocol. "He stood up and started screaming," Trump said of Ramos. "He's obviously a very emotional person," Trump said.

But moments later, Ramos returned to his seat in the front row — and Trump called on him. For five minutes, they tangled over immigration policy, an issue on which both men have passionately different views. It was one of the more compelling moments of the 2016 campaign.

"Good to have you back," Trump told Ramos, signaling to him to begin his questioning.

"Here's the problem with your immigration plan," Ramos said. "It's full of empty promises."

Ramos pointed out it would be unconstitutional to deny citizenship to what Trump calls "anchor babies," children born in the United States to undocumented immigrants. Trump disagreed, saying it could be done as an act of Congress and that some legal scholars argue the 14th Amendment should be changed.

"A woman's getting ready to have a baby," Trump said. "She crosses the border for one day, has the baby, all of a sudden for the next 80 years — we have to take care of" the child.

The next question from Ramos: How do you build a 1,900-mile wall across the U.S. border with Mexico?

"It's very easy," Trump said. "I'm a builder. ... What's more complicated is building a building that's 95 stories tall."

The questioning continued. At one point, Trump said, "I can't deal with this." A Trump aide interrupted and told Ramos, "Is there one question — one question?"

Yet Trump let the questioning continue, seemingly determined to prove his case. "I have a bigger heart than you do," he told Ramos. "We're going to do [deportations] in a very humane fashion."

Trump went on to assert that gang members in Baltimore, St. Louis and other cities are illegal immigrants.

"Listen, we have tremendous crime," he told Ramos. "We have some very bad ones. ... Do you mind if I send them back to Mexico?"

Ramos replied, "No human being is illegal, Mr. Trump."

The response: "Well, when they cross the border, from a legal standpoint, they're illegal immigrants when they don't have their papers."

When Ramos pressed Trump on polls showing his unpopularity with Latinos, Trump would not accept the premise of the question. First, he interrupted Ramos and turned the question on him: "How much am I suing Univision for right now? Do you know the number? I know you're part of the lawsuit."

Trump filed suit against the network in June, alleging defamation and breach of contract, after Univision ended its relationship with him and canceled plans to broadcast the Miss Universe pageant he owns following his controversial comments about Mexican immigrants.

"I'm a reporter," Ramos said.

"Five hundred million dollars," Trump replied. "And they're very concerned about it, by the way. I'm very good at this."