The term "doughface" was used for a Northern politician who sided with the South in opposing abolition in the time before or during the American Civil War. Billy correctly deduces that Alice's brother was a "doughface" because Gilbert named his dog "President Pierce" - after Franklin Pierce (1804-1869), the 14th president of the United States, who opposed the abolitionist movement as dangerous to the unity of the nation, even though he personally was opposed to slavery itself.
