DES MOINES — A day after a federal judge barred the University of Iowa from throwing off campus a Christian group at odds with the UI’s human rights policy, lawmakers took the first step toward enshrining free speech protections — including for student groups — in Iowa Code. “A public institution of higher education shall not deny any benefit or privilege to a student organization based on the student organization’s requirement that the leaders of the student organization affirm or agree to the student organization’s beliefs or standards of conduct,” according to one line in the proposed bill, which strikes at the heart of a federal lawsuit pitting the UI against the student group Business Leaders in Christ.The group, which calls itself BLinC, won a permanent injunction last week allowing it to keep operating and recruiting on campus.