The Dallas Morning News reports that Senator Ted Cruz released his birth certificate. This is not a joke.
According to the Dallas Morning News, Senator Cruz is both an American and a Canadian citizen. I guess that makes him equally eligible to be President of the United States or Prime Minister of Canada1.
Senator Cruz, after initially denying that he was a Canadian citizen, has now said the he is renouncing his Canadian citizenship. President Obama was also born a dual citizen of the US and the UK; his UK citizenship automatically ended when he reached age 23.
1While there are no specific eligibility requirements for the Prime Minister of Canada, it is generally held that the qualifications for a Member of Parliament apply, and that is to be a Citizen of Canada of voting age (18). See the Wikipedia article for more details.