Texas Sen. Ted Cruz has repeatedly defended his eligibility to be president this week, but wondering whether his Canadian birthplace would prevent him from running for the office has been on his mind since at least childhood, a schoolmate of his tells CNN. One of the Republican presidential hopeful’s college friends said he remembers talking with the future senator about his eligibility to serve as president. “I do recall specifically Ted once commenting that when he was a kid and he first learned about the natural-born citizen clause in the Constitution, like I suspect every other American child born abroad, he inquired whether or not he was eligible to be President. And he was quite pleased to discover that yes, indeed, that as a citizen born aboard he was eligible to run for the president,” said Michael Lubetsky, a Canadian who was on the Princeton debate team with Cruz. “Ted was certainly very confident that he was a natural-born citizen as determined in the U.S. Constitution.” Republican front-runner Donald Trump has raised questions about whether Cruz’s Canadian birth makes him ineligible to run for president. Cruz has argued that because his mother was a U.S. citizen, he meets the constitutional requirement that the president be a natural-born citizen. Lubetsky remembered Cruz, and other members of the debate team, coming to his home in Toronto and Cruz proudly telling his mother that Texas was so big that if it was flipped on its end, it would reach to the Canadian border. “There is no doubt that Ted identified himself as an American,” he said. “He was always an American and a Texan and that was certainly the case back then. We would cross the border to come to Canada and he would identify as an American.” Lubetsky said he remembered one occasion at a border crossing where Cruz identified himself as a dual citizen, “because I pointed to him and said he was a dual citizen.” “I think his normal routine was to identify himself as an American,” he said. A Cruz campaign spokeswoman did not respond to requests for comment. Following a 2013 investigation by the Dallas Morning News examining Cruz’s citizenship, the Texas senator formally renounced his Canadian citizenship the following year.