The aggressive theories and policy of the Southerners made the moderate opponents of slavery realize that the beneficiaries of that institution would, unless checked, succeed eventually in nationalizing slavery by appropriating on its behalf the national domain. A body of public opinion was gradually formed, which looked in the direction merely of de-nationalizing slavery by restricting its expansion. This body of public opinion was finally organized into the Republican party; and this party has certain claims to be considered the first genuinely national party which has appeared in American politics. The character of being national has been denied to it, because it was, compared to the old Whig and Democratic parties, a sectional organization; but a party becomes national, not by the locus of its support, but by the national import of its idea and its policy. The Republican party was not entirely national, because it had originated partly in embittered sectional feeling, but it proclaimed a national idea and a national policy. It insisted on the responsibility of the national government in relation to the institution of slavery, and it insisted also that the Union should be preserved. But before the Republicanism could be recognized as national even in the North, it was obliged to meet and vanquish one more proposed treatment of the problem of slavery—founded on an inadequate conception of democracy. In this case, moreover, the inadequate conception of democracy was much more traditionally American than was an exclusive preoccupation either with natural or legal rights; and according to its chief advocate it would have the magical result of permitting the expansion of slavery, and of preserving the Constitutional Union, without doing any harm to democracy.