Wow; its amazing that the school called him back and confronted OP on his political views. OP mentions that HR people would never do that for fear of being sued

Wow; its amazing that the school called him back and confronted OP on his political views. OP mentions that HR people would never do that for fear of being sued, has the university some form of immunity against being sued? Is industry a more liberal place than academia? Also what exactly was the keyword that put him into the 'enemy camp' - was it support of Israel, criticism of Carter or both of them that raised the red flag for them ?