How did Marius change the power structure in the roman republic?
Expanded military eligibility beyond the wealthy, which meant that the Roman government had to pay to equip the troops which they didnt do before when their soldiers provided their own gear. This changed the economic makeup of the Republic as well, by necessitating a larger treasury to pay for the higher cost of war, which the Romans offset by differently dividing the spoils of war and requiring tribute of subject provinces. Politically, he set a precedent of breaking the tradition whereby a person could only stand for the Consulship every ten years. His rival, Sulla, broke the precedent of a Dictator only serving six months, though Sulla retired voluntarily. This set the stage for the next generation (Caesar and Pompey) to buck the political establishment which led the the collapse of the Republic and the formation of Imperial rule.