The plot to kill Julius Caesar completely failed in its intended mission to restore the republic, and "Caesars" continued to rule for centuries. Violent upheaval is not always unwise: in many civilizations in which a ruler is becoming too powerful to rule with justice and wisdom, some citizens may feel that it is the only way. In Shakespeare's play, we read that Cassius is somewhat jealous of Caesar's power. Brutus, on the other hand, has misgivings about the idea of a sovereign ruler altogether.
Whatever the motivation for these assassins, the plan was set to fail, and the conspirators were doomed from the start because of one large oversight in the manner that the assassination was carried out. Most importantly, it would have been wise, if cruel, to kill Mark Antony as well as Caesar. Due to the fact that the conspirators did not want to come across as wanton murderers, however, they chose to spare his life. This marked a clear underestimation of Antony, made even more glaring by the fact that Brutus let him speak at Caesar's funeral.