Rob Ford, Manchester University’s professor of political science, ran the numbers for me. First past the post is a “non-linear” system or, as others might put it, a dazzlingly stupid way to organise a modern democracy. The Liberal Democrats could get 18% of the vote and be stuck with the 12 MPs they have now. They could get 23% and see that number rise to a mere 20 MPs. But hit 25% and they win 100 or more seats, with even more as the vote heads towards 30%, on condition that the Remain camp doesn’t destroy itself.