Leveling for differentiated instruction is a great way to allow students on all levels to use the same content and be challenged on their own level. I ran across a lesson plan that uses leveled questioning to interpret political cartoons on Boss Tweed. Most of the questions are generic so they will work for almost any political cartoon out there. The questions are located at the bottom of the lesson plan.
http://www.teacherspayteachers.com/Store/Kasha-Mastrodomenico is another place you can find social studies differentiated instruction lesson plans for middle school. If you teach American History at the middle school level, you should really check out our site. You will not be disappointed.
Best of luck differentiating!