A third person has withdrawn their nomination for a seat in Barack Obama's cabinet. Republican Senator Judd Gregg was set to become the commerce secretary before pulling out due to "irresolvable conflicts," although the US president has vowed to continue working at bi-partisan co-operation. Obama has previously admitted to making a "mistake" when two of his nominees for government posts withdrew amid controversy over unpaid taxes. What do you think of the way he is handling these situations?