Im fairly new to calling the plate, (just recently got my patch) I usually called a base or if I did get the plate, I worked lower level games or rec leagues. I've seen a lot unsportsman like stuff over the years both in coaching as well as umpiring, but last night was out of controll. The parents were leading the charge. Those poor kids will most likely grow up to be just like mom and dad if not worse!
Who is responsible for maintaining control of the game? Take charge and do not put up with it. Although the wording is different, every set of rules has a clause dealing with maintaining decorum and respect for the game. That provides the umpire with significant latitude when dealing with situations like this. Call time out, clear the field and bring both HC's to the circle out of earshot of players and fans. Explain very directly that you will not tolerate the described behavior from either team. Instruct them to go speak to their players and fans and resume the contest. Once resumed if an ejection is warranted at least they were warned.