According to Ted Cruz's father's statement, Ted Cruz's parents applied for and received Canadian citizenship before his birth in Alberta. Thus, his mother committed the act of obtaining naturalization of a foreign state, a potentially expatriating act. If this is true, then Ted Cruz is a 100% natural-born citizen of Canada, being born on Canadian soil of 2 naturalized Canadian parents.
In addition, until 1977, Canada required those seeking Canadian citizenship to swear an oath renouncing their allegiance to their previous country. This action, combined with behavior showing the person intended to relinquish his or her U.S. citizenship, has been ruled an expatriating act by U.S. courts. If Ted Cruz's mother obtained Canadian citizenship before 1977, then she swore this oath before a Canadian government official.
In addition, until 1977, Canada required those seeking Canadian citizenship to swear an oath renouncing their allegiance to their previous country. This action, combined with behavior showing the person intended to relinquish his or her U.S. citizenship, has been ruled an expatriating act by U.S. courts. If Ted Cruz's mother obtained Canadian citizenship before 1977, then she swore this oath before a Canadian government official.