Complex sentence: Las Vegas casino magnate Sheldon Adelson donated $500,000 towards the effort to thwart the bill, including a contribution of $1 million to the Drug-Free Florida Committee, who also fought the initiative.
Split into simpler sentences: Las Vegas casino magnate Sheldon Adelson donated $500,000 towards the effort to thwart the bill. Adelson's also contributed $1 million to the Drug-Free Florida Committee who also fought the initiative.