After the passage of the Kansas–Nebraska Act in 1854, armed conflict broke out in Kansas Territory, where the question of whether it would be admitted to the Union as a slave state or a free state had been left to the inhabitants. The radical abolitionist John Brown was active in the mayhem and killing in "Bleeding Kansas." The true turning point in public opinion is better fixed at the Lecompton Constitution fraud. Pro-slavery elements in Kansas had arrived first from Missouri and quickly organized a territorial government that excluded abolitionists. Through the machinery of the territory and violence, the pro-slavery faction attempted to force an unpopular pro-slavery constitution through the state. This infuriated Northern Democrats, who supported popular sovereignty, and was exacerbated by the Buchanan administration reneging on a promise to submit the constitution to a referendum—which would surely fail. Anti-slavery legislators took office under the banner of the newly formed Republican Party. The Supreme Court in the "Dred Scott" decision of 1857 asserted that one could take one's property anywhere, even if one's property was chattel and one crossed into a free territory. It also asserted that African Americans could not be federal citizens. Outraged critics across the North denounced these episodes as the latest of the Slave Power (the politically organized slave owners) taking more control of the nation.