When an ex UN officer turned professional election fixer working to ensure victory for a brutal dictator is scapegoated by his latest client, he uses every dirty trick he knows to try and win power for a little-known rebel group that not only promises freedom for their people – but payback for him.

"When an election fixer is targeted by the dictator he helped come to power, he must use every trick in the book to win power for a little known rebel group if he's to remove the dictator in order to survive."

This isnt bad, the structure is all right but there's way to must info being thrown at the reader.

Firstly, take the second line "working to ensure victory for a brutal dictator is scapegoated by his latest client" and condense it. Something as simple as "tricked by..." or "stabbed in the back by," will make it much easier to understand. We dont need all that info about working to ensure a latest victory etc

And do a similar thing with the second part, his goal. try and get it down to as few words as possible. It may be annoying cutting out all the 'good' bits but it makes it alot easier to follow whats going on