Ted Cruz
U.S. Senator Ted Cruz speaks to reporters on Capitol Hill in Washington. Reuters

Senator Ted Cruz’s release of his birth certificate to the Dallas Morning News on Sunday could be a clear indication of his intention to run for president in 2016, but there is still a gray area around his eligibility.

Cruz was born in Canada, but to an American mother, which makes him a U.S. citizen. And Canadian law experts who spoke to the Dallas paper say Cruz also is an automatic Canadian citizen because he was born in Calgary. While the Texas Republican has yet to announce a presidential bid, there are critics who question whether his dual citizenship might disqualify him from being president.

The U.S. Constitution doesn’t bar an individual with dual citizenship from assuming the nation’s highest office. It states: “No person except a natural-born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President.”

The problem lies in the definition of “natural-born citizen,” and this has opened a way for critics to question Cruz’s eligibility.

John C. Harrison, a constitutional law professor at the University of Virginia, said there is no well-established answer as to who is a “natural-born citizen.”

“It’s a long-standing question,” he said. The issue has been debated for more than 100 years. There are three possible situations, Harrison explained. First, there is someone born on U.S. soil and therefore a U.S citizen; second, people "in the middle" because they automatically got citizenship from having a parent who is American but were not born on U.S. soil; and third, those born in other countries who become naturalized as U.S. citizens later in life. The latter are ineligible to become president.

“Somebody like Cruz is in an intermediate position,” Harrison said. And this might prevent him from being president. “It’s not clear that somebody who acquires U.S. citizenship at birth but acquires it through his mother -- having been born in another country-- that person may not be a natural-born citizen. ... It’s not clear what the answer is, and if somebody like that is not 'natural born', well, the Constitution says you have to be natural born.”

Outside of a Constitutional amendment, Harrison said, Cruz himself could bring forth an answer if he’s elected president, and if the courts don’t present a challenge to that, and if Congress treats him as the nation’s leader.

“This is one of these things you might say is a little bit like testing your parachute by jumping,” Harrison said. “The only way really to find out is for such a person to be elected.”

Cruz’s office has not responded to a request for comment, but his spokeswoman Catherine Frazier told the Dallas paper that “to our knowledge, he never had Canadian citizenship, so there is nothing to renounce.”

If anything, Sen. Cruz is stepping out ahead of potential distractions if he throws his hat in the ring in 2016, said Scottie Nell Hughes, news director for the Tea Party News Network. (Cruz is generally recognized as very popular with the tea party universe.)

“Right now everybody is already getting aligned for 2016,” Hughes said. “Obviously this shows whether Ted Cruz is running for president or not, he’s definitely seen all the drama that’s gone into President Obama’s birth certificate issue and he wants to make sure that he nips this thing in the bud before it grows and continues on like we’ve seen with Obama."

There are still some who believe that Obama, who was born in Hawaii, isn’t a U.S. citizen and therefore wasn’t eligible to become president. But Hughes said Cruz is doing what Obama should have done when those rumors surfaced: Shut them down quickly.