The tribunate of Tiberius Gracchus in 133 BC led to a breakup of the long-standing norms of the republican constitution. Gracchus was successful in passing legislation to pursue land reform, but only over a norms-breaking attempt by Marcus Octavius—a tribune in the same year as Gracchus—to veto proceedings overwhelmingly supported by the people. Gracchus' legislation would challenge the socio-political power of the old aristocracy, along with eroding their economic interests. The initial extra-constitutional actions by Octavius caused Gracchus to take similarly novel norms-breaking actions, that would lead even greater breakdowns in republican norms. The backlash against Tiberius Gracchus' attempt to secure for himself a second term as tribune of the plebs would lead to his assassination by the then-pontifex maximus Scipio Nasica, acting in his role as a private citizen and against the advice of the consul and jurist Publius Mucius Scaevola.