'My party is full of racists': Former Colin Powell aide blasts GOP after Romney adviser says ex-Secretary of State is only supporting Obama because he's black -Retired Colonel John Wilkerson is a Republican who served as General Colin Powell's chief of staff -John Sununu claims Mr Powell is supporting the President's election campaign because of their shared race -Says the former US Secretary of State - who is African American - did not make decision based on policy -Poll show race for White House is racially divided with Obama supported by 80% of black and Hispanic voters but just 37%...