Answer: Whether Caesar was overly ambitious.
Explanation: In this speech from Act III, Scene II, of "The Tragedy of Julius Caesar" by William Shakespeare, the issue over which the claims and counterclaims of this speech mostly focus is whether Caesar was overly ambitious. Brutus has just said in his speech that he has killed Caesar out of his love for Rome. Then, Antony speaks to the crowd and makes the people think of what they have been told by Brutus and what Caesar really was. Through his claims and counterclaims, he wants to make them focus on whether Caesar was so overly ambitious as Brutus stated.