A certain percentage of the AP Language exam texts must be written before 1899. As much as you assume they will be difficult for your students, in reality they are probably even more difficult.
One advantage to this pre-1899 requirement is that older texts are often replete with classic rhetorical moves--one after another after another. For this reason, teaching the second essay (analysis) with older texts is productive. Thomas Paine's pamphlets are absolutely loaded with classic rhetorical moves.
Thomas Paine fits nicely into a politics unit or simply any AP Language curriculum that is taught in conjunction with American Literature/History.
This download includes two carefully selected excerpts from Paine's _Common Sense_ (1776). With the prompt, they could be used as straight analysis essay assessments or as guided readings, group readings, rhetorical technique scavenger hunts, etc. Each of the excerpts is accompanied with detailed annotations describing the Paine's usage of techniques such as...
lying in the mean (ethos)
Give your kids high quality American rhetoric of historical significance that will provide instructional value for as long as you teach.