So far the GOP API is useless, most of the methods do not work and the ones that do are still having issues.
I've spoken to the
gop.gov team about this and they informed me they were forced to launch before these features were ready.
Most of the data they offer though seems like it'll be member/bill data that is already widely available, but the documents methods could be interesting (hard to say what they will be as the documentation is 404)
-James