Ted Cruz is a natural-born citizen and he can be president. There is no ambiguity, no legal question. It is very clear.
Clear of course to nearly everyone but Donald Trump, Ann Coulter, and a somnolent American media who would rather have this faux-controversy than simply say to Trump he is factually wrong and move on.
Sigh. Here it is.
The Constitution, Article II, Section I, states one must be a "natural born citizen" to become president. That means immigrants who were born citizens of one country and naturalized to become American citizens later in life are not eligible. Natural born means the person was an American by birth, at birth. Yes, technically the Supreme Court has never been asked to rule on this, but the Supreme Court has never ruled on lots of things that are still true and lawful. That argument is pretty weak.
Cruz was indeed born in Canada, a foreign country. His mother was born in the United States. His father was Cuban. They lived in Canada, working in the oil industry. A child of an American citizen mother born abroad is an America citizen, absent some very specific circumstances that even Trump isn't challenging.
The determination of American citizenship for a child born abroad is formally adjudicated by the State Department, which documents the citizenship with a Consular Report of Birth Abroad (CRBA, or Form FS-240.) This happens multiple times a day at embassies all over the globe. Technically there is no actual requirement to even have that document -- it is only convenient proof of what are the circumstances of a birth abroad. Citizenship can be documented not just at birth, but at any time during a person's life.
This same set of laws is why Obama, whose mother was an American citizen, would have been an American citizen even if he'd been born in Kenya.
The natural born question is not new, but it has been so well-chewed over such that there is no need to do it again, as Trump is doing.
In 2008, the Senate passed a resolution that John McCain was allowed to run for president even though he was born in the Panama Canal Zone, which was technically not part of the United States, because his parents were Americans. Senators Barack Obama and Hillary Clinton both voted for it.
The Congressional Research Service published a report after the 2008 election supporting the fact that natural born citizenship means citizenship held at birth.
If we must have more, two of the best-known Supreme Court lawyers make the case that Cruz, as were McCain, George Romney (born in Mexico) and Barry Goldwater (born in Arizona when it was only a territory, not a state) before him, is eligible to run.
Neal Katyal, who served as Obama's acting solicitor general, and Paul Clement, who was solicitor general under George W. Bush (i.e., bipartisan support), wrote in the Harvard Law Review that "there is no question."
Cruz is eligible.