BUFFALO, N.Y. -- It's been a busy weekend for immigration attorneys, who constantly fielded calls related to President Trump's executive order that calls for a temporary immigrant and refugee ban from seven countries.

"Some of our clients are corporations that have offices throughout the world and they transfer people from various countries into the U.S. They're concerned about getting their people in, and we've got people who've held green cards and are wondering if they're gonna have issues," said Rosanna Berardi, managing partner at Berardi Immigration Law.

Berardi says the action Friday afternoon that left people detained at airports across the country was poorly executed.

"They could have done a lot better in terms of rolling this out and being ready for the issues that came up. That being said, it's a colossal system," Berardi said. "There are a million players. It's an executive order that speaks to national security. They didn't want to release it early on because they didn't want people to have notice of this, but from the government side, unfortunately it caused a ton of confusion."

Acting Attorney General Sally Yates directed Justice Department attorneys Monday not to defend the executive order. She was subsequently removed from her post, and replaced by former United States Attorney for Virginia Dana Boente.

This comes as Trump awaits his Attorney General pick, Sen. Jeff Sessions to be confirmed.

Berardi says the executive order is tightly drafted, and if its legality is challenged, it will likely be upheld.

"People are raising constitutional concerns, saying that this is discrimination based on religion, and as such violates the establishment clause of the U.S. Constitution," Berardi said. "That's one argument that people are making. If you look at the language closely of the order, though, in no way, shape or form does it point to religion. It points to countries that have been designated based on national security issues."

Following initial criticism of the action, President Trump pointed to his predecessor delaying the processing of Iraqi refugees in 2011 as a similar action.

Factcheck.org, which is run by the University of Pennsylvania, says that argument is not a proper comparison because President Obama was responding to a specific threat.

"The Obama administration was responding to a flaw within the system that came about when they got an intelligence tip that there was an Iraqi citizen who is now a refugee in the United States in Kentucky who was involved in planting and detonating IED's when he was in Iraq," said Factcheck.org director Eugene Kiely.

As for the effectiveness of the executive order, Berardi says she has mixed emotions, but is optimistic.

"It's a chance to pause, take stock, take inventory of what's working, what isn't from national security perspective, fighting terrorism. We're in a different day and age now," Berardi said. "People entering the United States for the most part are good people wanting to do good things, but we've all seen the few that have spoiled it for everyone else."