Regina George is Julius Caesar in Mean Girls. She is the leader that was feared to become too powerful or too popular. Regina was both loved and feared by the high school like Caesar. Then Regina was plotted against to ruin her reputation and taken down by Brutus and Cassius (Cady and Janice). Regina also resembles Marc Antony when she reveals the Burn Book to the school.
Cady and Gretchen both relate to Brutus. Cady was manipulated by Janice into taking down Regina. As she was doing that she became more like Regina herself and when Regina was taken down Cady took over the plastics. Gretchen is also like Brutus because she was Regina's best friend and also was turned against her. When she reads the paper in English class she shows her similarity to Brutus by saying "Why should Caesar get to stomp around like a giant while the rest of us try not to get smushed under his big feet. What’s so great about Caesar huh? Brutus is just as cute as Caesar. Brutus is just as smart as Caesar, and people totally like Brutus just as much as they like Caesar. And when did it become okay for one person to be the boss of everybody, huh? Because that is not what Rome was about! WE SHOULD TOTALLY JUST STAB CAESAR!!" She starts to notice Regina's popularity over everyone else and doesn't like how she is supposed to be better than everyone.
The candy canes that were sent out during the holidays are like the letter that was given to Brutus that Cassius forged from the people of Rome saying the want Brutus to lead instead. Cady sent a candy cane to herself from Regina and not to Gretchen causing Gretchen to see the real side of Regina even though it was through false pretences. It turned Gretchen against Regina.
The Burn Book resembles the will that Marc