The second part of Sumner's address dealt directly with the Fugitive Slave Act of 1860. It is much less convincing and suggests more of the characteristics of the special pleader with a difficult case. Sumner here undertook to prove that Congress exceeded its powers when it presumed to lay down rules for the rendition of fugitive slaves, and this task exceeded even his power as a constitutional lawyer. The circumstances under which Sumner attacked slavery were such as to have alarmed a less self-centered man, for the two years following the introduction of the Nebraska bill were marked by the most acrimonious debate in the history of Congress, and by physical encounters, challenges, and threats of violence. But though Congressmen carried concealed weapons, Sumner went his way unarmed and apparently in complete unconcern as to any personal danger, though it is known that he was fully aware that in the faithful performance of what he deemed to be his duty he was incurring the risk of assassination. The pro-slavery party manifested on all occasions a disposition to make the most of the weak point in Sumner's constitutional argument against the Fugitive Slave Law. He was accused of taking an oath to support the Constitution though at the same time intending to violate one of its provisions. In a discussion, in June, 1854, over a petition praying for the repeal of the Fugitive Slave Act, Senator Butler of South Carolina put the question directly to Senator Sumner whether he would himself unite with others in returning a fugitive to his master. Sumner's quick reply was, "Is thy servant a dog that he should do this thing?" Enraged Southerners followed this remark with a most bitter onslaught upon Sumner which lasted for two days. When Sumner again got the floor, he said in reference to Senator Butler's remark: "In fitful phrase, which seemed to come from unconscious excitement, so common with the Senator, he shot forth various cries about 'dogs,' and, among other things, asked if there was any 'dog' in the Constitution? The Senator did not seem to bear in mind, through the heady currents of that moment that, by the false interpretation he fastens upon the Constitution, he has helped to nurture there a whole kennel of Carolina bloodhounds, trained, with savage jaw and insatiable in scent, for the hunt of flying bondmen. No, sir, I do not believe that there is any 'kennel of bloodhounds,' or even any 'dog' in the Constitution." Thereafter offensive personal references between the Senators from Massachusetts and South Carolina became habitual. These personalities were a source of regret to many of Sumner's best friends, but they fill a small place, after all, in his great work. Nor were they the chief source of rancor on the part of his enemies, for Southern orators were accustomed to personalities in debate. Sumner was feared and hated principally because his presence in Congress endangered the institution of slavery.