Though Sumner’s private consultations with Lincoln played a role in his changing policy, the senator’s strategic maneuvering of public opinion arguably had an even larger impact. For the past several months, Sumner had been assisting a network of controversial New England abolitionists in their influence campaign targeted at the Republican mainstream. He had also been speaking out on his own. By shifting public opinion toward abolition, he gave Lincoln the necessary political cover to make this consequential decision.
