I'm not sure when the term latte liberal replaced the old champagne socialist as the favoured term of derision for the well-heeled leftie but it looks an increasingly useful metaphor for understanding how the deadlock in the Democratic presidential primary election might be broken. The two candidates have fought themselves to a standstill. In the closest race in any US presidential primary campaign in decades, Hillary Clinton and Barack Obama are more or less tied in total votes received and in delegates elected for the party's nominating convention. Super Tuesday, when almost half the country voted in the nearest thing...