As much as Brexit is associated with nationalism and opposition to the loss of control of borders etc there was also a strong social welfare component to the argument. Readers will recall the false but convincing claim made by Leave that the UK was sending GBP350m a WEEK to the EU and that this money would be better spent on revamping the National Health Service instead. Well, Leave walked away from that lie as soon as the result was in but it does go to show that nationalism in the sense it was used in the referendum has a significant social component to it. May missed this, ignored Remainers who make up half the population (even losing Kensington Chelsea, the wealthiest UK riding,  in the process!) and allowed Corbyn to claim a form a legitimacy he would not have enjoyed were he up against a credible foe. This outcome is a cautionary tale for politicians who make assumptions based on polls and for voters who are surprised  to get something other than what they thought they voted for