What if Mace killed Palpatine

So Anakin manages to be late due to speeder engine trouble or something, and he comes into Palpatine's office to see Palpatine's decapitated head lying on the floor, and Mace Windu saying that he didn't come peacefully to be arrested, murdered three Jedi (whose bodies are also lying on the floor), and Mace had no other choice.

Yeah... how do you think things would proceed from there? How would it affect the galaxy and the war?

 

Anakin wouldn't have turned to the darkside? Maybe?

That's a tough question though.

 

It would be the end of the story, the same Plot shield with Maul couldn't kill Obi-Wan in Naboo no matter what.

 

Anakin vs Mace. Even if Anakin killed him, the Republic would of arrested him and possibly executed him. There most likely would be some sort of other threat to rise up against the Republic in the following years. Maybe overtime the Republic would become more and more corrupt and a Rebellion would form. Maybe not though.