Well, they didn't just rig the election. They did it by accessing their (apparently google backed) email accounts. If that happened outside of a school setting, there'd be no question that the person violated the law. So, yeah, they did commit a crime. Maybe it shouldn't be prosecuted, but it's still a crime.
Plus they were dumb as posts to think it wouldn't be noticed. I'm surprised they weren't suspended. Word at Berkeley High is they got 300 "service hours."