Editor's note: This story has been updated throughout.

The normally ceremonial last day of the legislative session briefly descended into chaos on Monday, as proceedings in the House were disrupted by large protests and at least one Republican lawmaker called immigration authorities on the protesters.

State Rep. Matt Rinaldi, R-Irving, said he called U.S Immigration and Customs Enforcement while hundreds of people dressed in red T-shirts unfurled banners and chanted in opposition to the state’s new sanctuary cities law. His action enraged Hispanic legislators nearby, leading to a tussle in which each side accused the other of threats and violence.

In a statement, Rinaldi said state Rep. Poncho Nevárez, D-Eagle Pass, "threatened my life on the House floor," and that Rinaldi is currently under the protection of the Department of Public Safety as a result.

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“I was pushed, jostled and someone threatened to kill me,” Rinaldi said. “It was basically just bullying.”

Nevárez said in an interview with the Tribune that he put his hands on Rinaldi and told him to take his argument outside the House chamber. "But was I going to shoot the guy? No," he said.

After the incident, Nevárez tweeted in response to Rinaldi's claims: "He's a liar and hateful man. Got no use for him. God bless him."

DPS was not available to comment Monday because of the Memorial Day holiday.

Hispanic Democratic lawmakers involved in the altercation said it wasn’t physical but indicated that Rinaldi got into people’s faces and cursed repeatedly. Video shot from the House floor shows both Republicans and Democrats pushing each other.  

“He came up to us and said, ‘I’m glad I just called ICE to have all these people deported,'” said state Rep. César Blanco, D-El Paso, whose account was echoed by state Reps. Armando Walle, D-Houston, and Ramon Romero, D-Fort Worth.

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"He said, 'I called ICE — fuck them,'" Romero added. Rinaldi also turned to the Democratic lawmakers and yelled, “Fuck you," to the “point where spit was hitting” their faces, Romero said.

The skirmish started while lawmakers were taking a few moments to recognize House staff and clerks. Protesters who packed the House gallery erupted into chants in opposition of Senate Bill 4.

The controversial legislation has already been signed into law by Gov. Greg Abbott, a Republican. The law requires local cities and counties to cooperate with federal immigration authorities who request that law enforcement agencies continue to detain people suspected of being in the country illegally. It also bans local entities from adopting policies that ban their police officers from asking about the immigration status of people they detain. Among concerns raised by the law’s opponents is that it could lead to racial profiling of Texans during interactions with police, such as traffic stops.

“There’s no excuse for members making insensitive and disparaging remarks on the floor of the Texas House," Speaker Joe Straus said in a statement.

DPS quickly rushed in to break up the protest. They grabbed the banners from the protesters and pulled some of the people holding them out of the room. Eventually, they decided to clear the gallery of the protesters.

The ordeal became so loud that the House had to take a break from its proceedings for about 20 minutes. A handful of Democratic lawmakers looked up to the gallery and clapped. That’s when the altercation between the lawmakers on the floor started, according to the House Democrats.

Blanco said that at one point during the altercation, he pointed out that "Rinaldi" is an Italian name and that the Irish and Italians were once treated poorly in this country.

"He said, 'the difference between me and them is that I love this country,'" said Blanco, who added: "It's just disrespectful."

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Rinaldi said he was angry because Democrats in the House were “bragging about how great it was and they were inciting them to break the House rules and break Texas law.”

“I took issue with that,” Rinaldi said.

“We jawed back and forth and one of them physically assaulted me and another threatened my life, actually,” he said.

House Democrats involved in the altercation said that wasn’t the case and that they were simply cheering on members of the public who were exercising their First Amendment rights. It was Rinaldi who caused the scuffle on the floor, they argued.

"Matt Rinaldi gave the perfect example of why there's a problem with SB 4," said state Rep. Ramon Romero, D-Fort Worth. "Matt Rinaldi looked into the gallery and saw Hispanic people and automatically assumed they were undocumented. He racially profiled every single person that was in the gallery today. He created the scenario that so many of us fear."

In a press conference following the altercation, state Rep. Justin Rodriguez, D-San Antonio, said Rinaldi had also threatened to “put a bullet in one of my colleagues’ heads.”

Rinaldi said in his statement that he was speaking in self defense. 

In an earlier interview, Rinaldi defended the decision to call immigration authorities.

“We didn’t know what to do,” he said. “A lot of people had signs that said, ‘We are illegal and here to stay.’”

He said he called law enforcement “to incentivize them to leave the House.”

“They were disrupting,” he said. “They were breaking the law.”

Asked if the protest was too little, too late since the measure has already been signed into law, Adrian Reyna, an organizer with United We Dream, said the movement is just getting started.

“We have to show resistance the whole summer,” he said. “We have identified key representatives that we will take out of office who voted for SB 4. People are outraged, people are tired of the Legislature walking all over people.”

The protesters made that clear immediately after the House adjourned. After being shuffled out of the chamber, many of the hundreds of people gathered on the south steps of the Capitol. By then, the protest had turned into a celebration.

With a band playing Mexican cumbias, protesters held up signs reading, “NO SB4, NO HATE” as they danced along.

Massive protest engulfs the Capitol Rotunda as anti-SB4 protesters rally on May 29, 2017.  It's the last day of the 85th Legislative session on Memorial Day.
Massive protest engulfs the Capitol Rotunda as anti-SB 4 protesters rally on May 29, 2017. It's the last day of the 85th legislative session. Bob Daemmrich for The Texas Tribune

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