Cicero’s speech Pro Plancio was delivered in August 54 BC to defend Cnaeus Plancius, who had been accused of using bribery in order to win the election to the curule aedileship for the year 55. Plancius was arraigned pursuant to the Lex Licinia – issued only a year earlier, in 55 BC, by the consul M. Licinius Crassus – which condemned sodalicium, that is electoral corruption, organized through religious associations (sodalitates) which sometimes tended to turn into political clubs, from which votes could be bought (see Pro Plancio, secs. 45-47).
The prosecutor was Plancius’ unsuccessful opponent M. Iuventius Laterensis, who had lost the election, aided by another prosecutor (the …
Bernard, Jacques-Emmanuel. "Pro Plancio". The Literary Encyclopedia. First published 10 December 2013
[http://www.litencyc.com/php/sworks.php?rec=true&UID=20497, accessed 22 January 2017.]