Attorney Representing 2 Iraqis Detained at JFK Says Trump's Immigration Order Is Unconstitutional

— -- The lawyer representing Hameed Jhalid Darweesh, one of two Iraqi men who were detained and later released at John F. Kennedy International Airport on Saturday, said President Trump's executive order on immigration is unconstitutional.

On Saturday, about 55 people were detained in at least six different airports across the country because of the order, which temporarily suspends immigration for citizens and refugees of seven predominately Muslim nations.

Mark Doss, supervising attorney at the International Refugee Assistance Project, told ABC News Sunday that his clients are overwhelmed with happiness to "just be out" of detention.

"I can imagine it was a very traumatic and difficult time for them," he said.

Doss said that despite the ordeal, his clients still have faith in the United States and the ideals it represents.

"It’s really incredible to see their spirit in the face of what they went through," he said.

Doss' clients were not technically refugees and entered the U.S. on visas, a Trump administration official told ABC News.

One of the men was an electrical engineer and interpreter who worked with U.S. troops overseas for more than 10 years, according to Doss. Due to his service on behalf of the U.S., he was granted a special immigrant visa that gave him legal status to live in the country.

"It’s ironic that, given all of his service to the United States, that he would then be detained at the airport upon his arrival," Doss said, adding that his client had been threatened in his home country for his affiliation with the U.S.

"It's incredibly dangerous for them to be back in Iraq," Doss said. "They’re safe here, and we’re just glad they’re out of detention."

Doss said Trump's executive order violated due process rights and discriminated against Muslims.

"This is something that America does not stand for -– does not represent," he said. "As a nation, we treat all religions equally."

His two clients went through numerous steps to get their visas, including extensive background checks, he said. For one of his clients, it took years for his status to be approved.

"They cannot stay because they’re being targeted and will be killed," he said. "And the United States is a place that has always provided refuge to the most vulnerable individuals. So to be turning back refugees is completely contrary to American values and ideals."

Trump defended his order in a statement Sunday, saying, "America is a proud nation of immigrants and we will continue to show compassion to those fleeing oppression."

"America has always been the land of the free and home of the brave," Trump said, adding that the order is "not about religion" but "about terror and keeping our country safe."

Amin Karbasi, a research fellow at the University of California, Berkeley, said he may have to leave his "dream" job in order to be with his family. He recently returned to the U.S. after traveling to Iran to see his wife and 7-month-old daughter.

Karbasi had traveled to Iran with his family months ago, but they remained there while he came back to the U.S. for the start of a program at U.C. Berkeley. He had plans to go back to Iran next month to celebrate the Persian new year and bring his wife and newborn daughter back to the states with him when he returned.

Both he and his wife are green card holders, and his daughter is a U.S. citizen.

"It is shocking," Karbasi said of the order. "I always thought American people as extremely open and warm and kind and that has been constantly my experience in the last two and half years in the country."

Karbasi said his "home" is in the U.S. Just the thought of finding another place is "hurting" him, he said.

ABC News' Paulina Tam contributed to this report.