Tall, lanky Thomas Oatman manages to make clothes that never go out of style. His work for the New Republic label is based on classic American and English tailoring so his clothes have a substance that lasts. In his small Soho New Republic shop, spring is in store: cool seersucker suits, knee-length rubberized cotton raincoats, and Dupioni silk blazers inspired by Lily Pulitzer in luminous pastel shades of lime, melon, and vanilla line the walls.