Complex sentence: Marcone explains to Joe that Baynard holds the deciding vote to legalize sports gambling, and when Marcone tried to buy his vote, Baynard blackmailed Marcone, demanding $6 million or he would go to the police.
Split into simpler sentences: Marcone explains to Joe that he intends to legalize sports gambling buying the corresponding votes for that and that Baynard holds the deciding vote in this matter. When Marcone also tried to buy his vote for this purpose, Baynard blackmailed Marcone, demanding $6 million or he would go to the police.