"I think it's good to take a look at all of our constitutional amendments. But I'll tell you something: If you think it's a coincidence that this sudden discussion begins three months before an election, you'd be very, very mistaken," said Vermont Independent Sen. Bernie Sanders on "Top Line" last week.
Pennsylvania Democratic Sen. Arlen Specter, whose parents were immigrants to the U.S., called U.S. citizenship by birth a fundamental right.
"The political pandering on the immigration issue has reached the hysterical level," Specter said in an interview with ABC News. "To try to direct the effort at the children born in this country is just preposterous... How can newborn children protect themselves if politicians want to gain political gain... I would be shocked if this idea would gain political traction, but I'm being shocked on a daily basis by the United States Senate."
The 14th Amendment to the Constitution, which was enacted after the Civil War to grant citizenship to descendants of slaves, reads: "All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside."
"The drafter of the 14th Amendment provision on citizenship did make a statement that it would not include foreigners or aliens," said George Washington constitutional law professor Jonathan Turley. "However, other senators made it clear that they believed that this provision guaranteed birthright citizenship."
The courts have repeatedly upheld the notion that people who are born in the U.S. are American citizens and if Congress passed a law changing that, it would likely be repealed, experts say.
The Supreme Court has only addressed the issue once, clarifying in 1898 that citizenship does apply to U.S.-born children of legal immigrants who have yet to become citizens.
"The legislative history may be a little mixed, but the language of the amendment seems to speak clearly in favor of birthright citizenship, regardless of what the intent may have been," Turley said.
The United States is one of the few remaining countries to grant citizenship to all children born on its soil. The United Kingdom, Ireland, India and Australia, among others, have since revised their birthright laws, no longer allowing every child born on their soil to get citizenship.