At Rochester, in the summer of 1859, Mr. Seward furnished the Republican party a watch-cry when he called it "the irrepressible conflict," but two years before and repeatedly after Lincoln uttered the same idea in almost the same phrase. In three Presidential campaigns, in two contests for the Senate, and in almost every local political contest after 1840 slavery was the principal theme of his speeches, until the Douglas debate of 1858 caused him to be recognized as the most powerful advocate and defender of antislavery doctrines. Senator Douglas found great amusement in accusing Lincoln of a desire to establish social equality between the whites and the blacks, and in his speeches seldom failed to evoke a roar of laughter by declaring that "Abe Lincoln" and other abolitionists "wanted to marry niggers." Lincoln paid no attention to this vulgar joke until he saw that it was becoming serious, and that many people actually believed that the abolitionists were proposing to do what Douglas had said. He attempted to remove this impression by a serious discussion of the doctrine of equality, and in one of his speeches declared, "I protest against the counterfeit logic which concludes that because I do not want a black woman for a slave I must necessarily want her for a wife." In another speech he said, "I shall never marry a negress, but I have no objection to any one else doing so. If a white man wants to marry a negro woman, let him do it,--if the negro woman can stand it." [Illustration: ABRAHAM LINCOLN IN 1864 From a photograph in the War Department Collection] At another time he said, "If I saw a venomous snake crawling in the road, any man would say I might seize the nearest stick and kill it; but if I found that snake in bed with my children, that would be another question. I might hurt the children more than the snake, and it might bite them. Much more, it I found it in bed with my neighbor's children, and I had bound myself by a solemn compact not to meddle with his children under any circumstances, it would become me to let that particular mode of getting rid of that gentleman alone. But if there was a bed newly made up, to which the children were to be taken, and it was proposed to take a batch of young snakes and put them there with them, I take it that no man would question how I ought to decide."