How Ted Cruz, the Calgary-born U.S. senator, could become president

Texas junior Senator Ted Cruz, a Tea Party favourite, announced early Monday that he's running for the presidential nomination for the Republican Party.

The move would make Cruz the first high-profile Republican to formally announce his presidential bid, ahead of other likely contenders such as former Florida governor Jeb Bush and Wisconsin Gov. Scott Walker.

- ANALYSIS | Jeb Bush presidential bid challenge: Not being 'only adult in the room'

What differentiates Cruz from his competition, however, is that he was born in Canada — Calgary, Alta., in fact — to an American mother and a Cuban-born father. His heritage made Cruz a dual citizen at birth. Under U.S. law, being born to an American mother automatically gives you American citizenship, while being born on Canadian soil makes you a Canadian.

The U.S. Constitution doesn't preclude dual citizens from running for the presidency, but it requires presidents to be "natural born" citizens, which is commonly believed to be Americans born with citizenship even if they weren't born on U.S. soil.

So, Cruz is perfectly eligible for the White House. Two lawyers who represented presidents from both parties at the U.S. Supreme Court also recently wrote in the Harvard Law Review that Cruz meets the constitutional standard to run.

However, things are not so straightforward in the game of politics.

News of Cruz's Canadian birth surfaced in the U.S. media in mid-2013 — the same time he said he learned that he had Canadian citizenship, according to the paper that broke the story — and his opponents quickly jumped on the opportunity to call him "Canadian Ted." If the "birthers" who nagged Barack Obama about his citizenship were any indicator, it potentially could have caused a political headache for Cruz.

But any blossoming problem was quickly nipped in the bud.

Nine months after realizing he could have a passport emblazoned with the Arms of Canada and maybe even run for elected office in Canada, he officially renounced his Canadian citizenship in May 2014.

According to Cruz's spokeswoman, he said he was "pleased to have the process finalized" and that it "makes sense he should be only an American citizen."

The road to the White House, then, is clear of constitutional hurdles. But that was the easy part.