This month, presidential hopeful Ted Cruz has come under fire in regards to his eligibility for president.

Cruz was born in Canada. He moved to Texas when he was 4.

The Constitution says that, “No person except a natural born Citizen .”‰.”‰. shall be eligible to the Office of President.” The argument arises from the ambiguity of the statement “natural born citizen.”

Does the phrase mean only individuals born in the United States are eligible for presidency? According to the Harvard Law Review, the answer is no.

The Harvard Law Review posted a forum last March “On the Meaning of ‘Natural Born Citizenship.” In it, Neal Katyal and Paul Clement, both former solicitor general, give background on the phrase “natural born citizen.”

They said, “the original meaning of the phrase ‘natural born citizen’ includes persons born abroad who are citizens from birth based on the citizenship of a parent.”

The pair cited the Naturalization Act of 1790 as the reason for Ted Cruz’s eligibility. This act gave citizenship to children born abroad, if one of their parents held American citizenship.

Cruz’s mother was an American citizen at the time of his birth.

They continue that, “despite the happenstance of a birth across the border, there is no question that Senator Cruz has been a citizen from birth and is thus a ‘natural-born citizen’ within the meaning of the Constitution.”

Dr. Thomas Holyoak, professor of political science at Fresno State, said, “Ted Cruz is eligible to run, pretty much everyone who has thought seriously about this agrees. ­Nobody disputed Senator McCain’s eligibility in 2008, and he was also not born in the United States, but in the U.S. controlled Panama Canal Zone.”

Ironically enough, at the start of the month McCain commented on Cruz’s eligibility during an interview on Phoenix CBS affiliate KFYI-TV.

“I think there is a question. I’m not a constitutional scholar on that, but I think it’s worth looking into. I don’t think it’s illegitimate to look into it,” said McCain.

Jeremiah Folia, Central Valley regional chair for the Cruz campaign and campus chair, said, “one must understand what our founding fathers meant when they wrote “natural born citizen” in the constitution.”

“After the mid-seventeenth century civil wars in England, parliament created an act stating that all children who were born during the span of the wars ‘were born out of his majesty’s dominions. and whose fathers or mothers were natural born subjects of this realm’ were natural-born themselves (cited from the 1898 Supreme Court case United States vs Wong Kim Ark). Later, in 1708, it was again clarified, ‘the Children of all natural born Subjects born out of the Ligeance of Her Majesty, Her Heirs, and Successors shall be deemed adjudged and taken to be natural born Subjects of this Kingdom to all Intents Constructions and Purposes whatsoever.’ It was soon after, in 1787 that the constitution was signed. All English law was clear on what ‘natural born’ meant despite the somewhat ambiguous nature of the term in the constitution. By looking back on these acts and English statements, we can see clearly what the framers meant when they wrote ‘natural born.’”

Donald Trump sparked the conversation at the last GOP debate, asking Ted Cruz if he was even eligible to run.

Cruz responded saying, “Back in September, my friend Donald said he had his lawyers look at this in every which way, there was nothing to this birther issue.”

He said, “since September, the Constitution hasn’t changed. But the poll numbers have.”

The two candidates are leading the polls as the Iowa Caucuses draw near, and at the time of the GOP debate, Senator Cruz was up by four points.

“Donald Trump is simply using this to cast doubt in the minds of people who easily swayed by such wild charges, or who want to be swayed, including many of the same people who were convinced that President Obama was born in Kenya when he was clearly born in Hawaii,” Holyoak said.

Trump is currently leading the polls again. As of Sunday, Fox News released a poll out of Iowa with Trump up by 11 points.

Trump is still sticking to his guns when it comes to Senator Cruz’s eligibility. On Friday he tweeted, “Cruz did not renounce his Canadian citizenship as a U.S. Senator- only when he started to run for #POTUS. He could be Canadian Prime Minister.”