How did the roman rebublic fall apart?

The Roman Republic began to fall apart years before it finally fell due to the cronyism and unyielding attitudes of certain members of the senatorial class. Powerful families made alliances more for their own advancement than for the good of the state. Elections were often rigged. Tribunes bought. By the time Julius Caesar came to power, the senate was split into two main groups, the Optimates, who wanted things the way they had always been, and the Populists who were for change. By taking advantage of this split, Caesar was able to rise to the position of Dictator and then Dictator for Life, brushing aside the authority of the senate and the Roman people. After Caesar's death the government retained the appearance of a republic, but in fact, was controlled by the triumvirates and their factions. After Actium, Octavian/Augustus transformed the republic into the principate.