Charles Sumner moved on from distinguishing between moral duties to reject evil at home and political duties to oppose it from afar with a standard repudiation of designs to interfere with slavery in the slave states. He positioned himself on the antislavery left, but not so far over as to talk himself out of politics. He repeated the normal demands of late 1850: the repeal of the Fugitive Slave Law, abolition for the District of Columbia, prohibition of slavery in the territories, no new slave states admitted to the Union, and then flirted with more. Sumner declared himself and his free soil party for abolition of the domestic slave trade, especially at sea where the US flag often sheltered it but also, by implication, between states.
But Charles Sumner had a wider vision still, one shared then by few in the North but which would grow in popularity as the 1850s wore on:
The Slave Power must be overturned, -so that the National Government may be openly, actively, and perpetually on the side of Freedom.
That did not, Sumner stressed, mean the overthrow of slavery. He wanted the institution’s political influence gone. That power
having its origin in Slavery, which has been more potent, sinister, and mischievous than any in our long history. This Power, though unknown to the Constitution, and existing in defiance of its true spirit, now predominates over Congress, gives the tone to its proceedings, seeks to control all our public affairs, and humbles both the great political parties to its will.
He had the Constitution wrong, but American politicians routinely do that. Sumner hadn’t missed the true situation, though. Slavery created a powerful “common interest” among enslavers. They themselves would agree, though couching it in terms of the special needs of their institution for security. Sumner lacked the time to trace its full history
the undue share of offices it has enjoyed, and the succession of its evil deeds. Suffice it to say, that, for a long period, the real principle of this union was not observed by the Free States. In the game of office and legislation the South has always won. It has played with loaded dice, –loaded with Slavery.
That got a good laugh out of the crowd, but Sumner had facts and laughs on his side. At the time of his speech, a total of three men who never owned slaves had occupied the Presidency, two Adamses and Martin Van Buren. None had won re-election and no northern president would until the slave states opted out of the election of 1864. The South had an effective veto on all national legislation courtesy of the Senate. The slave states dominated Cabinet after Cabinet, the Supreme Court, and exercised decisive influence in both national parties. Sumner likened it to the workings of a fake automaton playing chess, with a man behind the curtain actually doing the work. The Slave Power occupied the spot behind the curtain, a “living force” that, now unmasked, they must defeat to restore the nation to its original design.