A preposterously optimistic goal: “The candidate says we can balance the budget by next year, but I think that's pie in the sky.”
pie in the sky definition
pie in the sky
An empty wish or promise, as in His dream of being hired as a sports editor proved to be pie in the sky. This expression was first recorded in 1911 in a rallying song of a union, the International Workers of the World (or "Wobblies"): "Work and pray, live on hay, you'll get pie in the sky when you die."