Jasim Nusaif, 71, in a photograph held by his son. He was among hundreds of former Baath Party members swept up in recent arrests. His family said the party expelled him in the 1980s.Credit...Michael Kamber for The New York Times BAGHDAD — Prime Minister Nuri Kamal al-Maliki has moved swiftly to consolidate power in advance of the American military withdrawal, offering a glimpse of how Iraq’s post