Norville, meanwhile, took over as Today co-anchor in January 1990, and spent the next year covering major news stories and interviewing subjects ranging from Margaret Thatcher to Paula Abdul. But the damage had already been done. Pauley’s successor continued to receive chilly treatment in the press and viewers steadily tuned out of Today in favor of Good Morning America.In early 1991, Norville went on maternity leave after giving birth to her first child and Katie Couric—then the morning show’s national political correspondent—was picked as substitute co-anchor. Norville never sat on…