Could Meghan Markle and Prince Harry's Child Be a US President and In Line For the Throne?

It's official: The Duke and Duchess of Sussex are expecting their first child, due in Spring of 2019. But the Internet has been pondering the future of the new royal since last year when Meghan Markle and Prince Harry got engaged.

One viral tweet asked: If the royal has children with the American actress, what would their citizenship be? And, following this train of thought to its inevitable conclusion, would it be possible for their kid to be both a U.S. President and in line for the throne?

Let's start with the question of Markle's citizenship. A spokesperson for Kensington Palace confirmed to CNN that Meghan will, in fact, become a British citizen — a process that takes a number of years. But they added it was "too early to say" if she would retain dual nationality. According to the the UK government's website, Markle would have to live in the U.K. for at least three years before starting the process, anyway.

Markle could choose to renounce her U.S. citizenship after she becomes a British citizen—but she doesn't have to. Royal expert Marlene Koenig put it this way to Town & Country: "If she remains a U.S. national, her children will have dual nationality just like Madeleine of Sweden's children."

Koenig points out that the reason Markle and her child would renounce American citizenship would be to avoid paying double taxes.

"I would expect that when they reach adulthood, they would go through the process of renouncing. People do it all the time, many for tax purposes," Koenig says. "The U.S. may be the only country that taxes the income of citizens who live outside the country. Meghan may have investments that will earn income—and even abroad, she will have to pay US income tax.

"Princess Marie Chantal of Greece renounced her US citizenship—she was born in London but her father was American—a few years ago," Koenig says. "And now she is living in the U.S. again." (Marie Chantal is the daughter of American businessman Robert Miller, who made a fortune in duty free shopping.)

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OK, but if the royal heir doesn't renounce American citizenship, could they pull a Ted Cruz and run for President of the United States? The Constitution has a clause indicating that "No Person except a natural born Citizen, or a Citizen of the United States ... shall be eligible to the Office of President." Could these theoretical Mountbatten-Windsors (yes, that will be their last name) claim that though they were born outside of the U.S., they are still "natural born citizens," just as Cruz, who was born in Canada to an American mother and Cuban father, claimed when he ran for president in the 2016 election?

Well, according to the Harvard Law Review, it looks like the answer is technically yes:

All the sources routinely used to interpret the Constitution confirm that the phrase “natural born Citizen” has a specific meaning: namely, someone who was a U.S. citizen at birth with no need to go through a naturalization proceeding at some later time. The Supreme Court has long recognized that two particularly useful sources in understanding constitutional terms are British common law and enactments of the First Congress. Both confirm that 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.

There you have it. Markle and Harry's child could be both President of the United States and heirs to the British throne.

This post has been updated. Prince Harry and Meghan Markle are the Duke and Duchess of Sussex, not the Duke and Duchess of Cambridge.