Complex sentence: The Republicans also accused the Pierce administration of allowing a fraudulent territorial government to be imposed upon the citizens of the Kansas Territory, allowing the violence that had raged in Bleeding Kansas, and advocated the immediate admittance of Kansas as a free state.
Split into simpler sentences: The Republicans also accused the Pierce administration of allowing a fraudulent territorial government to be imposed upon the citizens of the Kansas Territory, thus engendering the violence that had raged in Bleeding Kansas. They advocated the immediate admittance of Kansas as a free state.