Center for Immigration Studies Director of research Steven Camarota said there are likely hundreds of thousands of people receiving US citizenship every decade simply because their parents were in the United States temporarily.
"As Americans, we need to think about that. American citizenship is one of the most valuable things in the world and do we want to give it away in this way?," said Camarota.
More than 4.5 million anchor babies are born in the U.S., exceeding the roughly four million babies born to legal American citizens every year.
Camarota said state governments treat everyone with a US birth certificates as an automatic US citizen.
"We've estimated that this birth tourism, people coming to America, explicitly right before they give birth so that their children are awarded US citizenship, there are about 33,000 of these a year ," said Camarota.
He said it would be a type of Visa fraud to say they're coming to America for a visit, but actually coming here to give birth.
Camarota said Congress would have to make the change, since the Constitution is ambiguous. To change it would have to amend the Constitution, otherwise, it would have to go through the courts, eventually to the Supreme Court.
The Supreme Court has never explicitly ruled that the Citizenship Clause of the 14th Amendment (U.S.-born children of illegal aliens) must be granted automatic American citizenship.