WATCH: Senators answer questions about 'due process' as Trump cracks down on illegal immigration

"We need judges that are not going to be demanding a trial for every single illegal immigrant. We have millions of people who have come in here illegally, and we can't have a trial for every single person. That would be millions of trials," Trump recently told reporters on Air Force One.

"I'll also say, throwing out little kids who are U.S. citizens, it's wrong, it's dangerous. It is certainly not fair to them or their parents, but it really does affect everybody. I mean, tossing out a 2-year-old who's a U.S. citizen is crazy," Kelly said. 

But Republicans who spoke to Fox News Digital weren't so sympathetic, as they doubled down on their support of the Trump administration deporting illegal immigrants. 

"The law does not require someone to actually have a jury trial," Sen. James Lankford, D-Okla., countered to Fox News Digital. "A hearing can be done. It's not a trial. It's not a jury trial. That's not the right of someone that's not legally present in the country."

Lankford said illegal immigrants are only entitled to a hearing, not a trial before a jury before deportation, which is supported by the due process clause of the Fifth Amendment. 

"No, it's not necessary," said Sen. Tommy Tuberville, R-Ala., agreeing with Trump. "These people are illegal."

"Basically, the courts have said under a habeas proceeding, there needs to be notice," said Schmitt. "But the question is, what does that notice mean? Is it an hour, is it a day or is it a week? I think what you're ultimately going to see, not under the Alien Enemies Act, but under the habeas cases, is that there's going to be a relatively short window, and [Trump's] going to be able to proceed with these deportations."

"A lot of it depends on whether the courts do the right thing or not," Miller said.