Some elections are landmark events. As in 1918, 1945 or February 1974, they're called not simply because another lustrum has elapsed but because some major issue requires resolution ('What will postwar Britain be like?'; 'Who governs Britain?'). Brexit is obviously the big issue overshadowing this election, but there's far less distance between Theresa May and Jeremy Corbyn on Brexit than between her and Kenneth Clarke or Michael Heseltine, dinosaurs bedded in the Euro-swamp where May herself still languished not a year ago.