Yes, Ted Cruz is Eligible to Be President Even Though Canadian-Born
There's simply no question that a person born abroad to a US citizen is a 'natural-born Citizen.'
Rumors that freshman Texas Senator Ted Cruz is considering a 2016 presidential bid have generated not only appropriate scorn and derision but also questions about whether the Calgary-born Cruz is even eligible to run. The Atlantic’s David Graham quashes that one:
Cruz was born in Calgary, Canada, while his parents were living there. His father is now an American citizen, but was not at the time; his mother, however, was born in the United States.
Helpfully, the Congressional Research Service gathered all of the information relevant to Cruz’s case a few years ago, at the height (nadir?) of Obama birtherism. In short, the Constitution says that the president must be a natural-born citizen. “The weight of scholarly legal and historical opinion appears to support the notion that ‘natural born Citizen’ means one who is entitled under the Constitution or laws of the United States to U.S. citizenship ‘at birth’ or ‘by birth,’ including any child born ‘in’ the United States, the children of United States citizens born abroad, and those born abroad of one citizen parents who has met U.S. residency requirements,” the CRS’s Jack Maskell wrote. So in short: Cruz is a citizen; Cruz is not naturalized; therefore Cruz is a natural-born citizen, and in any case his mother is a citizen. You can read the CRS memo at bottom; here’s a much longer and more detailed 2011 version.
The second of these is a pretty fascinating read. There’s really not a lot of case law here, since the ‘natural-born’ requirement only applies to the president and vice president, but there’s simply no question that a person born abroad to a US citizen meets the standard. That goes double, incidentally, if the foreign country they were born in is Hawaii.