At the beginning of Act II of Shakespeare's Julius Caesar, what reasons does Brutus give in his soliloquy for killing Caesar?

Brutus says he has to kill Caesar because the people are
going to crown him King and with that role he would become too powerful and do damage to
Rome.  He says he knows of many powerful men before who were fair and just until they
were given too much power.  Once they obtain arbitrary rule, they turn their back on
their friends an countrymen.

Brutus professes that he has
no personal grudge against Caesar and in fact thinks of him as a good friend, but he
sees Caesar's potential danger to Rome as reason enough to kill him which is evidenced
in his famous simile in lines 32-34:  "And therefore think him as a serpent's egg -
Which, hatched, would as his kind grow mischieveous - and kill him in the
shell.

Therefore, he must kill him, not because of any
personal animostiy, but for the good of Rome.