What were the causes of the failure of the Roman republic?

This is an important and great question. Perhaps, it is best to
start this post by stating that it might be helpful to ask a different question.Why did the
Republic last for so long? Even during the turbulent times of the Republic, the elite class
tried to follow Republican forms. This is Erich Gruens basic point in his magisterial book, The
Last Generation of the Roman Republic. With that said, one has to come to terms with that fact
that things did change. At one point the Republic was a distant memory and the Empire and
emperor were realities. What happened? With such a huge question, there were many...