Lincoln, in replying, agreed that “all the States have the right to do exactly as they please about all their domestic relations, including that of slavery.”  But he said that the proposition that slavery could not enter a new country without police regulations was historically false; and that the facts of the Dred Scott case itself showed that there was “vigor enough in slavery to plant itself in a new country even against unfriendly legislation.”  Beyond this issue of historical fact, Douglas had already taken and still dared to maintain a position which proved to be singularly ill chosen.  The right to hold slaves as property in the Territories had lately, to the infinite joy of the South, been declared by the Supreme Court to be guaranteed by the Constitution; and now Douglas had the audacity to repeat that notion of his, so abhorrent to all friends of slavery,—­that this invaluable right could be made practically worthless by unfriendly local legislation, or even by the negative hostility of withholding friendly legislation!  From the moment when this deadly suggestion fell from his ingenious lips, the Southern Democracy turned upon him with vindictive hate and marked him for destruction.  He had also given himself into the hands of his avowed and natural enemies.  The doctrine, said Mr. Lincoln, is “no less than that a thing may lawfully be driven away from a place where it has a lawful right to be.”  “If you were elected members of the legislature, what would be the first thing you would have to do, before entering upon your duties? Swear to support the Constitution of the United States.  Suppose you believe, as Judge Douglas does, that the Constitution of the United States guarantees to your neighbor the right to hold slaves in that Territory,—­that they are his property,—­how can you clear your oaths, unless you give him such legislation as is necessary to enable him to enjoy that property?  What do you understand by supporting the Constitution of a State, or of the United States?  Is it not to give such constitutional helps to the rights established by that Constitution as may be practically needed?...  And what I say here will hold with still more force against the judge’s doctrine of ‘unfriendly legislation.’  How could you, having sworn to support the Constitution, and believing it guaranteed the right to hold slaves in the Territories, assist in legislation intended to defeat that right?” “Is not Congress itself under obligation to give legislative support to any right that is established under the United States Constitution?” Upon what other principle do “many of us, who are opposed to slavery upon principle, give our acquiescence to a Fugitive Slave Law?” Does Douglas mean to say that a territorial legislature, “by passing unfriendly laws,” can “nullify a constitutional right?” He put to Douglas the direct and embarrassing query:  “If the slaveholding citizens of a United States Territory should need and demand congressional legislation for the protection of their slave property in such Territory, would you, as a member of Congress, vote for or against such legislation?” “Repeat that,” cried Douglas, ostentatiously; “I want to answer that question.”  But he never composed his reply.