Is Trump's travel ban constitutional? Immigration law experts from both sides weigh in.

It's been one week since President Donald Trump issued what has surely become the most controversial action of his presidency thus far: his executive action temporarily banning travel to the U.S. by people in seven countries in the Middle East.

The order bars people from Iran, Iraq, Libya, Somalia, Sudan, Syria and Yemen from traveling to the U.S. for 90 days, raising serious questions from some on the Left as to whether the action is even constitutional. Already, more than a half-dozen lawsuits have been filed in opposition to the order, including challenges by the ACLU and the Council on American-Islamic Relations, CNN reported.

But the question of whether any of these legal challenges can hold any water in a federal courtroom remains to be seen.

"What we have here is a situation where it's very clear the president has been given authority when the standard [of] the national interest would be adversely affected," William Stock, president of the American Immigration Lawyers Association, told TheBlaze during an interview Friday.

"We've allocated to the president the ability on short notice to suspend visas if it's an emergency," Stock added, referring to the Alien and Sedition Acts of 1798, which grants the president the authority to suspend visas from immigrants of certain countries when the U.S. is at war with those countries.

"On the other hand," Stock added, "we have a First Amendment principle, which says that Congress and the president cannot favor one religion over another. Those two constitutional principles are colliding with each other at the moment."

Stock said the question now becomes which of these two constitutional principles will be given more importance.

The statutory provision Trump cited as the legal basis for his order (8 U.S. Code § 1182) requires the president to give a reason for suspending visas. Such reasons can include anything from individuals having spreadable diseases to them posing a risk to the American public's safety.

Similar actions have been taken by previous presidents. The Chinese Exclusion Act of 1882, signed into law by President Chester Arthur, banned Chinese laborers from immigrating to the U.S. amid concerns of unemployment, particularly on the West Coast. Then, in 1924, President Calvin Coolidge signed the Johnson-Reed Act, which limited the number of immigrants coming to the U.S. while completely barring Asian immigrants.

Trump's order is similar in that it bars immigrants from certain countries for the stated reason of national security. But according to Stock, the effort becomes complicated in part because of which nations are not included. The order does not include any of the four countries from which the 9/11 hijackers originated: Saudi Arabia, Egypt, the United Arab Emirates or Lebanon.

Further, Stock said the courts will likely consider the recent statements made by members of Trump's inner circle. He pointed to one comment, specifically, by former New York City Mayor Rudy Giuliani, who said on Fox News last weekend that Trump asked him for advice on what Trump first announced in December 2015 as a "total and complete shutdown of Muslims entering the United States."

"I’ll tell you the whole history of it: When he first announced it, he said ‘Muslim ban,'" Giuliani said, the Hill reported.

"He called me up, he said, ‘Put a commission together, show me the right way to do it legally," Giuliani added.

Stock said comments like these are sure to be taken into account.

"There's a lot of law behind how a court will look behind the language of a particular statute...to say, 'well, wait a second, what's really going on here,'" Stock said. "When you have a president who comes out and says, 'I'm going to throw this in the face of the courts,' that 'I get to do whatever I want,' that's a recipe for having the courts take a serious second look at the constitutional principle that the president is trying to use."

But Hans van Spakovsky, an immigration law expert at the conservative Heritage Foundation, told TheBlaze during an interview Friday that Stock is just "blowing smoke." Van Spakovsky said Congress has given the president of the United States "very broad discretion" when it comes to immigration.

Van Spakovsky pointed to the statute Trump cited in his executive order, which states, in part:

Whenever the President finds that the entry of any aliens or of any class of aliens into the United States would be detrimental to the interests of the United States, he may by proclamation, and for such period as he shall deem necessary, suspend the entry of all aliens or any class of aliens as immigrants or nonimmigrants, or impose on the entry of aliens any restrictions he may deem to be appropriate.

"There's no constitutional issue here. There's not even a federal statutory issue," Van Spakovsky said. "There's just no way anybody could question that because they've got 100 percent authority over immigration. And they [Congress] gave to the president, they delegated the ability to suspend the entry of any alien into the country and that executive order falls fully within that statute."

As for the order not including majority Muslim countries such as the UAE, Van Spakovsky pointed out the governments in those countries are able to work with the U.S. to thoroughly vet immigrants applying for American visas. That's not the case with the countries included in Trump's order.

"This doesn't go after all the countries in the world from where terrorists have sprung. It goes after the seven worst countries in the Middle East, all of which are failed or failing countries," Van Spakovsky explained.

At this point, it's unclear as to how far up in the court system the several challenges to Trump's executive order might go. But even if one or all of them find their way to the U.S. Supreme Court, Van Spakovsky seemed confident that Trump's order would withstand the justices' scrutiny.

"I think the Supreme Court would easily uphold the legality and constitutionality of this executive order," he said, adding that the only way liberal justices on the nation's highest court wouldn't side with the conservative justices "is if they totally ignore the Constitution and the law."

"Hopefully, that wouldn't happen," Van Spakovsky said.