How has the case for Scottish independence evolved since 2014?

Scottish First Minister Nicola Sturgeon will set out a "route map" on Tuesday to a second independence referendum. In a 2014 referendum, 55 percent of voters in Scotland chose to stay in the UK – and much to the chagrin of Unionists, the Scottish government plans to hold another next October. But from Brexit to a scandal-plagued prime minister occupying Downing Street, a lot has changed since the last vote.