Why did Gaius Marius turn against Saturninus and Gaius Glaucia?

The relationship between Gaius Marius and his political allies, Lucius Appuleius Saturninus and Gaius Servilius Glaucia, deteriorated in 100 BCE due to a combination of political ambition, jealousy, and the escalating lawlessness of his partners.

Several factors contributed to this breach:

• Jealousy and Competition: Marius may have felt that Saturninus was stealing his political influence or "thunder" among the populace.1
• Political Aspirations: As a six-time consul and the savior of Rome, Marius aspired to be accepted as an elder statesman (princeps) by the aristocracy. He did not seek revolution or tyranny, and he hoped to be honored by the very class that had previously looked down on him as an upstart.2
• Escalating Lawlessness: The methods employed by Saturninus and Glaucia—including blatant illegality, electoral violence, and the murder of a candidate for the consulship—reached a level that no consul could tolerate.13
• Strategic Necessity: When the Senate issued the "last decree" calling on the consuls to save the state from the chaos caused by his allies, Marius felt compelled to act. By suppressing the violence, he sought to fulfill his duty to the state and distance himself from the revolutionary actions of his former partners.12