Scipio Nasica’s next major political involvement would be that in the murder of Tiberius Gracchus. Gracchus rose to office at a time when the Roman Republic was bloated with the effects of extensive expansion abroad; a huge influx of slave labor and foreign wealth, a change in the function of agriculture and devaluation in the crop market were causing a massive domestic crisis, challenging the fundamental values of Roman culture (there is a debate over whether it was a grain crisis or a manpower crisis). Gracchus had taken the office of "tribune" and was passing laws of reform to help rectify this domestic crisis, though his legislation was empowering the "plebs" of Roman society. The majority of the Senate, who favored the patricians, felt threatened and aligned with Scipio Nasica and his cousin Scipio Aemilianus, who would lead the opposition against Gracchus. Nasica eventually became responsible for the assassination of Gracchus during elections in 133 BC. Scipio Nasica had gathered the senators to Gracchus’ bloody death claiming that the "tribune" desired to become king of Rome. To commit the assassination Scipio Nasica covered his head with the hood of his "pontifex maximus" robe, which possibly denoted the killing as a ritualized sacrifice for the good of Rome. After his assassination, Scipio led a witch hunt to eradicate any surviving supporters of Gracchus. Those who escaped the purge afterwards demanded that Scipio be held responsible for murder.