Hearing the replies of Lewis Cass, Stephen Douglas, and James Mason to his Crime Against Kansas speech, Sumner understood that they demanded a reply. If he said nothing, unlike him in any event, it would amount to conceding their points. Sumner wouldn’t let that happen and so rose to speak again. He started with Cass,
venerable with years, and with whom I have had associations of personal regard longer than with any person now within the sound of my voice. […] The Senator from Michigan knows full well that nothing can fall from me which can have anything but kindness for him.
During his tour of the nation, Sumner had called on Cass and his marriageable daughter in Michigan. I don’t know how much further back they go, but that had to count for something. Lewis Cass, Sumner’s dear friend, had turned on him:
He has said on this floor to-day that he listened with regret to my speech. I have never avowed on this floor how often, with my heart brimming full of friendship for him, I have listened with regret to what has fallen from his lips. I have never said that he stood here to utter sentiments which seemed beyond all question disloyal to the character of the fathers and to the true spirit of the Constitution
Sumner and Cass differed in the past, but Sumner had never gone public with it. He maintained their friendship and Cass repaid him with accusations approaching treason. Sumner sounds genuinely blindsided. He may have thought higher of Cass than Cass did of him. He at least implied that he did. Wounded feelings only got one so far, though. Politics in every era has no dearth of bruising scrapes. Sumner moved on to the substance, that Cass accused him of having Michigan’s history wrong.
my statement of that case was founded upon the actual documents. No word was mine: It was all from Jackson, from Grundy, from Buchanan, from Benton, from the Democratic leaders of that day. When the Senator criticised me, his shaft did not touch me, but fell upon them.
Don’t argue with Sumner; argue with the people he quoted. Yet Cass didn’t dispute the words themselves. He argued instead about the particulars of the situation in Michigan which gave rise to the lines in question. One could argue that Cass’ shaft -let us imagine an arrow, Gentle Readers- did touch, because Sumner sidestepped the argument. But Sumner’s reference to “actual documents” reminds us that he did the research. The Crime Against Kansas speaks of Michigan’s situation in some detail, more than one would expect from an idle reference. Cass has a fair point in that Michigan’s statehood did not progress exactly like Kansas’ bid had, but he himself equivocates between a statehood rejected by the legislature and one accepted by a dubious popular assembly. Both men could make a case from those facts, but it does seem to hinge more on technical details than points of principle.