Of course, Cardinal Reinhard "We are not a subsidiary of Rome" Marx neglects to mention the pope owes loyalty to Christ as well, as Pope Benedict taught:

"The power of teaching in the Church involves a commitment to the service of obedience to the faith.  The Pope is not an absolute monarch whose thoughts and desires are law.  On the contrary, the Pope's ministry is a guarantee of obedience to Christ and His Word.  He must not proclaim his own ideas.  Rather constantly bind himself and the Church to obedience to God's word in the face of every attempt to adapt it or water it down and every form of opportunism.”