The Brexit referendum was supposed to succeed by failing. Things did not go according to plan. There’s a lesson here for Alberta and Canada, as the province heads for a likely Albexit independence referendum later this year. But before we talk about the future, let’s revisit an unhappy past. Former British prime minister David Cameron wanted to renegotiate Britain’s relationship with the European Union, and the threat of a vote on Britain’s continuing membership in the EU was seen as a helpful negotiating tool. Mr. Cameron had also been subject to years of referendum pressure from his party’s fringe, which...