The Iowa Republican Party, which is hosting its straw poll in the city of Ames this weekend, is waiting to see what New Hampshire decides before announcing a date for its caucuses.
Mr Cooper said he had been further angered by the treatment of anti-nuclear protesters, and also by an incident involving Walter Wolfgang, then 82, who was thrown out of the 2005 Labour Party conference for shouting "nonsense" at then foreign secretary Jack Straw as he delivered a speech.