He had previously brought to trial Titus Menenius Lanatus, whose failure to intervene in the Battle of the Cremera during his consulship in 477 had led to the utter destruction of the Fabii and the loss of an important strategic position, and Spurius Servilius Structus, who as consul in 476 recklessly attacked a Veientine force that had taken the Janiculum, and only been rescued from disaster by the arrival of his colleague.
Menenius had escaped with a fine and his life, but soon sickened and died; while Servilius was acquitted due to the boldness of his defense, and the support of his colleague, Aulus Verginius Tricostus Rutilus.
Vopiscus and his colleague, protected only by their twenty-four lictors, all of them plebeians, and some of them already being manhandled by the people, were forced from the forum and took refuge in the senate-house until the anger of the crowd died down.
Although the more aristocratic senators urged harsh tactics for dealing with the situation, calmer heads seeking to avoid further strife between the orders prevailed, and an uneasy truce saw out the year.
In 471 BC, he carried a law allowing the concilium plebis to assemble by tribe, rather than by wards, and granting them the power to elect their own tribunes, giving the plebeians a new measure of political independence.