There is a fight for the soul of the GOP. Ever since this book:
Ryan, Cantor, and McCarthy have had a target on their backs. Cantor is gone, McCarthy is skulking in the shadows and Ryan is constantly under fire.
Here is a decent overview of the Bannon/Ryan dynamic.
http://nymag.com/daily/intelligencer/2016/11/why-steve-bannon-hates-paul-ryan.html
Ryan thinks job #1 in America is to empower corporations and the rich. He makes all of his interns read
Atlas Shrugged. Bannon thinks that job #1 in America is to protect white identity and Western European culture. He thinks that Ryan is selling out the US to globalist corporate interests.
Bannon wants to reform the GOP. He wants to move them away from policies based on money and taxes and shift them to policies based on race and identity. Ryan wants to keep the status quo and Bannon wants to blow it all up.