The issue about Ted Cruz’s eligibility to be president seems to be having much greater staying power than I had anticipated. Donald Trump has been making it an issue sufficiently strongly that Cruz has felt obliged to even release his mother’s birth certificate. For me at least, it initially seemed like a chance just to make fun of Republicans who find themselves hoist with their own petard, the tables turned on them after they raised such a big fuss over president Obama’s eligibility. But with Cruz, the issue has suddenly taken a rather more serious turn due to recent developments.

To fully understand it, we need to get into the weeds a bit. For some background, the US constitution is characteristically terse about what the requirements for the presidency are. In Article II, Section 1 all it says is:

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; neither shall any person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States.

The catch is that the key phrase ‘natural born Citizen’ was not defined. Could it preclude, for example, anyone born by Caesarian section, the loophole that famously destroyed Macbeth’s sense of invincibility that was bestowed upon him by an apparition that promised him that “none of woman born shall harm Macbeth”, when MacDuff revealed that he “was from his mother’s womb untimely ripp’d.”

That would be ridiculous, of course, but the ridiculousness of this birther issue has plumbed such surprising depths that it would not surprise me in the least to hear someone raise it.

Currently it is the consensus that the phrase means anyone who becomes a citizen at birth. That clearly encompasses anyone born within the US to parents who are US citizens. The 14th Amendment passed in 1868 granted birthright citizenship to anyone born in the US even if their parents were not citizens. So problems only arise if someone is born outside the United States and then we are entering territory that people can dispute and have disputed.

For example, what if one was born in a US territory that was not a state at that time? This was the case with 1964 Republican nominee Barry Goldwater who was born in the territory of Arizona in 1909 three years before it became a state. The answer seems to be that this is acceptable.

What if the person was born to US citizens on a US military base in another country, as was the case with 2008 Republican nominee John McCain who was born in Panama? That also seems to pass muster.

The real disputes have been when a child is born outside the US or its territories. Then the issue of citizenship is adjudicated according to State Department guidelines based on statutes that cover situations when both parents are citizens, when only one is a citizen and the parents are married, and when only one is a citizen and they are not married. (I discussed this issue in some depth here and here back in July 2009 when people were challenging president Obama’s eligibility.)

In Cruz’s case, the undisputed facts are that he was born in 1970 in Canada, his Cuban-born father was not a US citizen, his mother was born in the US, and his parents were married at the time of his birth. The relevant passage in the guidelines is then:

A child born abroad to one U.S. citizen parent and one alien parent acquires U.S. citizenship at birth under Section 301(g) of the INA provided the U.S. citizen parent was physically present in the United States or one of its outlying possessions for the time period required by the law applicable at the time of the child’s birth. (For birth on or after November 14, 1986, a period of five years physical presence, two after the age of fourteen, is required. For birth between December 24, 1952 and November 13, 1986, a period of ten years, five after the age of fourteen, is required for physical presence in the United States or one of its outlying possessions to transmit U.S. citizenship to the child.) The U.S. citizen parent must be the genetic or the gestational parent and the legal parent of the child under local law at the time and place of the child’s birth to transmit U.S. citizenship. [My emphasis-MS]

What Trump seems to be saying, and he is correct in that, is that the constitutionality of these guidelines has never been tested. Trump is also pointing to the fact that Cruz only renounced his Canadian citizenship in 2014 and that makes him suspect. Hence Trump says that Cruz risks being ruled ineligible if he is challenged and that he should pre-emptively go to the courts now and get a ruling. In fact, Florida Democratic congressman Alan Grayson has promised to file such a suit if Cruz becomes the nominee.

Carly Fiorina has added fuel to the fire by saying that it was ‘odd’ that Cruz did not renounce his Canadian citizenship until 2014. Prominent conservative activist lawyer Larry Klayman thinks that Cruz is ineligible and controversial sheriff Joe Arpaio also has doubts about Cruz’s eligibility. But Rush Limbaugh says he has no doubts about Cruz’s eligibility.

Since Cruz’s mother was born in the US and has spent the required time within its borders, that would seem to settle the issue in his favor, at least as far as meeting the requirements of the State Department guidelines. His supporter Iowa congressman Steve King (who was one of those who made a big fuss about Obama’s eligibility) has said in response that the issue is quite simple, “there are only two kinds of citizens: natural born and naturalized. If he’s a citizen, and he’s not naturalized, he’s natural born. That satisfies the Constitution.” Cruz himself has repeated the argument, that since he was never naturalized as a US citizen, that makes him a citizen by birth because “The child of a U.S. citizen born abroad is a natural-born citizen.”

But there is a third possibility and that is that Cruz is not a US citizen at all. This is where the new developments come in because they raise the question of whether Cruz’s mother had lost or renounced her citizenship while in Canada.

Grayson has also challenged the idea that Cruz’s mother was a U.S. citizen at the time of his birth, in 1970. An earlier report published by Breitbart showed that both of Cruz’s parents were listed on a Canadian federal voter list from 1974. Since only Canadian citizens are permitted to vote in federal elections there, the presence of Cruz’s parents’ names on the list raises the possibility that they may have been Canadian citizens at one time.

And because becoming a Canadian citizen requires an oath of allegiance—and Section 349 of the U.S. Immigration and Nationality Act stipulates that American citizens who swear allegiance to another country may lose their American citizenship—it seems possible that Cruz’s mother may have lost her American citizenship. This would mean that Cruz was not a U.S. citizen at the time of his birth and is therefore ineligible to become president.

However, Diane Benson, a spokeswoman for Elections Canada, tells Newsweek that the presence of a person’s name on a voter roll does not necessarily mean that he or she was legally allowed to vote. It was not immediately clear if that rule was the same in 1974, when Cruz’s mother’s name appeared on the list.

The voter lists purportedly were of people over the age of 18 who were Canadian citizens and thus entitled to vote. Cruz’s campaign has been on the defensive with these new revelations and has been responding with false statements, never a good sign. At the very least, getting on the list did seem to require an affirmative agreement by the person to be placed on the list.

Even if Cruz’s mother had become a Canadian citizen, she may still have retained her US citizenship. But this raises issues about whether if one takes an oath of allegiance to another state, does that mean that one is renouncing US citizenship? Under what conditions does one retain US citizenship? After all, some people do have dual citizenship status with other countries. Grayson says that this is something that only the courts can decide.

In addition to the question of whether Cruz’s birth in Canada disqualifies him from being considered a natural-born citizen, for which there are clashing historical claims, Grayson notes there’s disagreement about whether both parents of U.S. citizens born overseas must be citizens.

And then there’s Cruz’s mother, Eleanor Cruz.

Grayson says Cruz may have forfeited her U.S. citizenship by taking a Canadian oath of citizenship, and that he’s seen no evidence she actually was born in the U.S.

Cruz’s mother “may have elected to give up her U.S. citizenship — she wasn’t there on a visitor’s visa for five years, that’s for sure,” he says.

Grayson says “if his mother, who clearly worked in Canada for years and years, did so while becoming a Canadian citizen and taking an oath, which is how you do it in Canada, she lost her citizenship by U.S. law, specifically Section 349 of the Immigration and Nationality Act.”

Section 349 says Americans can lose their citizenship if they take loyalty oaths to foreign governments.

“There’s a counter-argument, there are some court cases that have watered down Section 349,” Grayson concedes. “It’s up to some court to decide whether Section 349 means what it say or not or whether it applied to her circumstances. We need more information at this point.”

What is interesting is that Cruz’s antagonizing of his Republican colleagues, especially in the US Senate, is now returning to bite him. Normally one would expect them to vigorously defend one of their own, saying that this is much ado about nothing. But that is not the case. The silence among his senatorial colleagues has been deafening. In fact McCain has even said that he does not know if Cruz is eligible. It is possible for the senate to pass a resolution declaring him to be natural born, the way that Hillary Clinton and Barack Obama co-sponsored for their opponent McCain in 2008, but senate majority leader Mitch McConnell has ruled out any such action to counter Trump’s charges against his own party colleague.

Yale professor of constitutional law Laurence Tribe, who taught Obama, Cruz, and chief justice John Roberts, also says that the questions about Cruz’s citizenship and the constitutionality of him becoming president are ‘unsettled’ as matters of law and that there is a rich irony if this case were to go to trial.

In his emails to the Guardian, Tribe discussed Cruz’s own approach to constitutional issues, noting that under “the kind of judge Cruz says he admires and would appoint to the supreme court – an ‘originalist’ who claims to be bound by the historical meaning of the constitution’s terms at the time of their adoption – Cruz wouldn’t be eligible because the legal principles that prevailed in the 1780s and 90s required that someone be born on US soil to be a ‘natural born’ citizen.”

He added: “Even having two US parents wouldn’t suffice for a genuine originalist. And having just an American mother, as Cruz did, would clearly have been insufficient at a time that made patrilineal descent decisive.

“On the other hand, to the kind of judge that I admire and Cruz abhors – a ‘living constitutionalist’ who believes that the constitution’s meaning evolves with the needs of the time – Cruz would ironically be eligible because it no longer makes sense to be bound by so narrow and strict a definition.”

Tribe said: “There is no single, settled answer. And our supreme court has never addressed the issue.”

The potential for irony does not end there. If it turns out that Cruz’s mother had ceased having US citizenship at the time he was born in Canada, then Cruz would not be a US citizen at all. That would make him an undocumented immigrant and a candidate for deportation, something that he and many other Republicans strongly favor for people in that situation. Since he has renounced his Canadian citizenship, he would also be a stateless person. Perhaps he could apply to for refugee status though then he would have to undergo rigorous screening to ensure that he was not an ISIS agent. It is not clear which country would be willing to take him in as a refugee, given that he is such an unpleasant person. The Canadian government of former prime minister Stephen Harper would have done so but I am not sure about the Justin Trudeau administration. They have been very welcoming to refugees but Cruz may be a bit too much to stomach.

There are many ways in which this could be resolved in Cruz’s favor. The simplest would be for the listing of his mother in the 1974 electoral voter list to be an honest mistake. The next would be that his mother did become a Canadian citizen but in such a way that her US citizenship was not renounced. The most messy would be that she did become a Canadian and lose her US citizenship but only after he was born in 1970.

Perhaps a word is necessary in anticipatory response to those who accuse me of partisan double standards, of ridiculing birthers when they challenged Obama but taking them seriously when they attack Cruz. But the two cases are quite different except for the fact that both mothers were born in the US while the fathers were not US citizens. In Obama’s case, he was born in Hawaii in 1961 after it became a state in 1959 so there was no ambiguity at all. To create one, birthers had to concoct an elaborate story where his mother secretly went to Kenya to give birth and then she and the rest of the family created a cover story that he was born in Hawaii that involved the collusion of the hospital authorities there that recorded his birth, the state’s registrar’s office that issued a birth certificate, and the Hawaiian newspapers that published the birth announcement. And they went to all this trouble because his mother, just 16 years old at the time, was aware of the obscure State Department guidelines that would prevent her infant son from someday becoming president. If she cared so much about preserving his future eligibility, she could have simply come home for the delivery.

It will be interesting to see if this topic comes up at the next debate on Thursday. I cannot imagine Trump missing such an opportunity to bring the issue up before a national audience.