There are two good reasons why it is colon (short for colonial.):
First, the classic theme of independent, hardworking good guys
being threatened by the heavy evil central government makes good
Second, the two Star Wars films we have seen before, ( and previous
films by Lucas,) are fantasy. Not hard Science Fiction, but Fantasy.
Clones do not make good fantasy. How do you explain this stuff to the
Still, the turn around of Darth to a good guy, now that's fantasy!