She joins Harvard Law Professor Laurence Tribe in raising concerns that Cruz may not meet the "natural born citizen" requirement for presidency under the Constitution. She previously wrote a paper about the topic in 2014.
In the Washington Post op-ed, McManamon argued that if one turns to the "common law" definition of "natural born citizen," he or she will find that 18th century English jurist William Blackstone defined the term as a "born within the dominions of the crown of England" and that U.S. founding father James Madison called birth place "the most certain criterion" of allegiance.
She acknowledged that other legal experts -- specifically former solicitors general Neal Katyal and Paul Clement -- have interpreted "natural born citizen" to mean anyone who was a U.S. citizen at birth, but criticized that interpretation because it depends on "radical 18th-century British statutes."
Cruz was born to an American mother in Canada in 1970. The debate over his eligibility for president was inflamed when Donald Trump made it an issue on the campaign trail.