Scheer won't explain travel to America as citizen without valid U.S. passport - 2019-10-16
Earlier in the campaign, Scheer confirmed he held dual citizenship in Canada and the United States, the latter passed to him by his American-born father. Scheer said his parents applied for the citizenship and a U.S. passport on his behalf when he was a child, but that he hasn't renewed his passport since becoming an adult.
He is in the process of relinquishing his U.S. citizenship after filing the paperwork in August a few weeks before the campaign began. He said he intended to do so when he won the Conservative leadership, but did not get around to it for more than two years.
U.S. passports are valid for up to 10 years, which means Scheer couldn't have held a U.S. passport for at least the last 12 years if he hadn't renewed it as an adult.