Senators, consuls, and the Assembly all played pivotal roles in the political and social spheres of the Roman Republic.
Senators were chosen from former officeholders and military leaders and held their positions for life, unless convicted in court. The Senate itself was composed of 300 members was responsible for a variety of duties. Such responsibilities included determining the tasks that magistrates would perform, fixing the funds that governors would receive to finance operations, selecting the magistrates whose terms would be extended, and ruling on the acceptability of treaties. The Senate also played a role in foreign policy. It is important to note that there was little formal, legal basis for the Senate's power. Rather, being a part of the Senate was a position based largely on tradition, custom, and wealth.
Consuls were chief magistrates of the Republic and commanded armies. They had a type of power known as imperium, or absolute authority when out in the field. Becoming a consul was the highlight of any statesman's career, and only two consuls that served jointly were chosen per year.
The Assembly was more open to the average citizen and had a legislative function. Assemblies had a direct democracy model, so members of the Assembly did not need to be elected representatives to cast their ballots.