Political parties can and do die. The Whigs of the 19th-century United States and the Progressive Conservative Party of 20th-century Canada were once major forces; today they are no more. Once-mighty Pasok in Greece is today on the critically-endangered list, and the hollowed-out French Socialists could soon head that way too (see Lucy Wadham).
Such talk might sound fanciful when applied to the Labour Party, especially after a bungled Conservative budget. It still runs the big cities, retains over 200 MPs, and has recently doubled its membership. The unremittingly dreadful polls are not on their own enough to start reading Labour’s last rites, not even after those polls translated into dire totals of real votes at two recent by-elections, one of which—Copeland—was arguably the worst defeat for an official opposition at the hands of the government since the 1870s.