They would not submit to a conception of the American political system, designed exclusively to give legal protection to property in negroes, and resulting substantially in the nationalization of slavery.
They insisted upon a conception of the Constitution, which made the national organization the expression of a democratic idea, more comprehensive and dignified than that of existing legal rights; and in so doing the Northerners undoubtedly had behind them, not merely the sound political idea, but also a fair share of the living American tradition.

The Southerners had pushed the traditional worship of Constitutional rights to a point which subordinated the whole American legal system to the needs of one peculiar and incongruous institution, and such an innovation was bound to be revolutionary.

But when the North proposed to put its nationalistic interpretation of the Constitution into effect, and to prevent the South by force from seceding, the South could claim for its resistance a larger share of the American tradition than could the North for its coercion.

To insist that the Southern states remain in the Union was assuredly an attempt to govern a whole society without its consent; and the fact that the Southerners rather than the Northerners were technically violators of the law, did not prevent the former from going into battle profoundly possessed with the conviction that they were fighting for an essentially democratic cause.
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.