There’s something about Mace Windu that has not yet been revealed: he is a traitor to the Jedi!  Not a Sith, for we know that he opposes the rule of the Dark Side Adepts, but he also opposes the corrupt senate, Republic and ultimately the Jedi Order that defends it.  An apparently reluctant proponent of the idea that the Jedi could rule in place of the politicians, he ultimately battles Palpatine for that very prize!