The existence of slavery in the southern states was far less politically polarizing than the explosive question of the territorial expansion of the institution in the west. Moreover, Americans were informed by two well-established readings of the Constitution regarding human bondage: that the slave states had complete autonomy over the institution within their boundaries, and that the domestic slave tradetrade among the stateswas immune to federal interference. The only feasible strategy available to attack slavery was to restrict its expansion into the new territories. Slaveholding interests fully grasped the danger that this strategy posed to them. Both the South and the North believed: "The power to decide the question of slavery for the territories was the power to determine the future of slavery itself."