Gallego, a strident critic of President Donald Trump, said Friday's arrest of Daniel Ramirez Medina, 23, will only spread fear and distrust in immigrant communities.
It "confirms what we have all suspected: The Trump administration is indiscriminately targeting undocumented immigrants, including Dreamers, in raids across the country," Gallego said in a written statement. "Daniel Ramirez Medina should be released immediately."
"Arresting and deporting any of the 750,000 Dreamers who are currently contributing to our economy is nothing to be proud of." — Congressman Ruben Gallego
The arrest extends the confusion nationally about Trump's plans to change the status quo on U.S. immigration, refugees and foreign travelers.
His January 25 executive order, known popularly as the "immigration ban," sent shock waves around the world before it was put on hold by a federal judge from Washington, and later by the U.S. Ninth Circuit Court of Appeals.
Last week, immigrant advocates from around the country criticized the arrest of an undocumented mother of two in Phoenix, Guadalupe Garcia de Rayos.
Rayos, who had previously been ordered to self-deport, was detained and deported by the U.S. Immigration and Customs Enforcement bureau after she made a routine check-in with authorities.
About 750,000 people are now working legally under the program.
His parents brought him to the United States when he was 7. He applied for and received DACA work status two years ago.
Trump hasn't canceled the DACA program — yet. Nor was banishing people brought to the country as kids one of Trump's campaign promises.
But the Ramirez arrest shows again that these are different times.
Ramirez is a "self-admitted gang member," ICE spokesman Rose Richeson said in a statement released to the news media.
ICE arrested Ramirez's father this week because he had been deported previously. While at his home, ICE agents asked one of his sons if he was in the country legally. He was taken to a holding facility after telling them he had a work permit.
Mark Rosenbaum, a lawyer who's representing Ramirez pro bono, told the New York Times that ICE "repeatedly pressured" Ramirez to falsely admit he was in a gang. He now "unequivocally denies" gang affiliation, according to Rosenbaum.
Ramirez challenged the detention in court on Monday, arguing that it violated his Fourth Amendment rights.
He's now being held in Tacoma and is waiting to stand before an immigration judge for removal proceedings. About 20 demonstrators showed up at the detention facility on Tuesday night to protest the action.
Ramirez has a 3-year-old son living in California with his mother.
"Mr. Medina’s detention raises serious concerns about the legality of ICE’s deportation efforts," Gallego said in his statement, adding that ICE should brief Congress on "the full scope of their deportation activities."
Gallego pointed out that the president recently told Time magazine that he would "work something out that's going to make people happy and proud."
"Arresting and deporting any of the 750,000 Dreamers who are currently contributing to our economy is nothing to be proud of," he said.