Never before — at least, not in living memory — has there been such a disconnect between north and south Britain. We vote together, but cast our ballots in very different contests. Scotland and England, semi-detached in the past, are more estranged than ever. The mildewed contest between David Cameron and Ed Miliband touches few hearts north of the Tweed; the battle between Labour and the SNP still mystifies many of those sent north to observe the strange happenings in Scotland.