His strenuous opposition to the reforms of Marcus Livius Drusus during his consulate of 91 BC, in defense of the "collusionist policy" of the governing class with the publicani chiefs, was instrumental in the outbreak of the disastrous "Bellum Italicum", the Social War. This should have made him a natural Marian during the violent politics and civil wars of the 80s BC, and he did well under the Marian government, holding high office. But he was more of an individualist and survivor than committed to any cause, and took advantage of the political amnesty offered by Sulla in 83 BC to change sides, along with other Marians of later importance, such as Marcus Aemilius Lepidus (cos. 78) and Marcus Junius Brutus (tr. pl. 83), P. Cethegus, and Pompey.