UNC law professor: Trump 'dead wrong' on citizenship

"We have to start a process where we take back our country," Trump said on the O'Reilly Factor on Tuesday. "Our country is going to hell."

Theodore Shaw, a University of North Carolina at Chapel Hill law professor and director of the UNC Center for Civil Rights, said that, regardless of Trump's position, the 14th Amendment of the U.S. Constitution is clear on birthright citizenship.

"The children of illegal or undocumented immigrants are citizens of the United States if they are born in the United States. Period," Shaw said. "The argument that Donald Trump is making is one that is ill informed, and he's just dead wrong."

Ratified in 1868, the 14th Amendment directly countered the U.S. Supreme Court's Dred Scott decision, which said black people could never be American citizens.

Shaw said it was "perhaps the most insidious decision the Supreme Court handed down."

U.S. courts have consistently upheld challenges to the amendment over the last 150 years, he said, making any question of citizenship for those born in America to illegal immigrants "an open-and-shut case."

"That distinction with respect to the birthright citizenship clause doesn't mean a thing," Shaw said. "If someone is born in the United States, no matter what the status of her or his parents is, that person is a citizen of the United States."

Paul even introduced legislation in 2011 that would deny birthright citizenship to children of illegal immigrants born in the U.S.

But Shaw said the country could deny birthright citizenship only if the Constitution itself is changed.

"Legislation cannot change the Constitution, cannot amend the Constitution. The Constitution is the supreme law of the land," Shaw said. "There's only one way the birthright citizenship clause can be abandoned, and that is by Constitutional amendment."