A good persuasive topic would be some thing easy. Like how you hate how Kool Aid just appear out of nowhere and break walls for reason that he's only there because, for him, it is important to say "OH YEAH!!!!"
Legislature involving teens--
* Legal drinking age,
* Legal driving age,
* Issues such as texting behind the wheel, etc.
EDIT: * Also the bullying legislature being passed in some states and considered in others due to all the recent suicides :/
School related issues--
* School starting time (should it be later, should it be kept the same? there's a lot of debate going on about that),
* School uniforms,
* Blocking schedules vs "normal" schedules (1h30 min classes vs 45 min classes),
* Summer vacation vs Year-round school (keep in mind that year-round school means that summer break is basically broken up and redistributed across the year so you have a bunch of 3-week breaks, they don't just delete summer vacation, that would be awful o.o)
* Mandatory online courses: Some school in Florida made taking an online course mandatory for graduating and 5 teachers lost their jobs since kids started taking classes online and didn't need teachers anymore, that's a controversial topic you could probably fine a fair bit of information on.
Misc.--
* The increased use of drugs to treat children (with issues such as ADD/ADHD, etc) has gotten attention in recent years because people believe doctors are over-diagnosing kids.
* And then there's the typical controversial stuff: evolution, abortion, gay rights, legalization of pot.