Complex sentence: The Washington State Legislature passed a new primary system in 2004, which would have created a nonpartisan blanket, or top-two, primary system, with an open primary as a backup, giving the governor the option to choose.
Split into simpler sentences: The Washington State Legislature passed a new primary system in 2004, which would have created a nonpartisan blanket, or top-two, primary system. It provided an open primary as a backup, giving the governor the option to choose.