Benjamin worked to deny Douglas the 1860 Democratic presidential nomination, feeling he had turned against the South. Douglas contended that although the Supreme Court, in "Dred Scott v. Sandford", had stated Congress could not restrict slavery in the territories, the people of each territory could pass legislation to bar it. This position was anathema to the South. Benjamin praised Douglas's opponent in his re-election bid, former congressman Abraham Lincoln, for at least being true to his principles as an opponent of the expansion of slavery, whereas the senator considered Douglas to be a hypocrite. Benjamin was joined in his opposition to Douglas by Senator Davis; the two were so successful that the 1860 convention was not able to nominate anyone and split into Northern and Southern factions. The Northerners backed Douglas while Southern delegates chose Vice President John C. Breckinridge of Kentucky. Despite their agreement in opposing Douglas, Benjamin and Davis differed on some race issues: in May, Benjamin voted for a bill to aid Africans liberated by U.S. naval vessels from illegal slave ships, in order to return them to their native continent from Key West. Davis and many other Southerners opposed the bill.