The demographic groups most underrepresented on law faculties include white Christians and Republicans, according to research by Northwestern University School of Law professor James Lindgren. His working paper, “Measuring Diversity: Law Faculties in 1997 and 2013,” challenges the notion that women and minorities are underrepresented in teaching the law. Those groups actually have made significant gains.... But viewpoint diversity did not improve. For example, 59 percent of lawyers in 2013 identified as white Christians, and that group comprised nearly 57 percent of the working population. Yet white Christians made up just 34 percent of law professors. Republican men comprised 23...