At MSNBC, a Professor as TV Host

Week seven of Melissa Harris-Perry’s introductory course in African-American studies at Tulane University includes a lecture about “the hollow prize” — a theory that African-Americans tend to be elected as mayor only after a city has tipped into economic decline. One day last summer, when Ms. Harris-Perry was filling in for Rachel Maddow on MSNBC, she recast the class lecture as a television segment, invoking Detroit; her adopted home, New Orleans; President Obama; and tax policy. “I’ve given that lecture a million times — a million times,” Ms. Harris-Perry said in a recent interview. “But I do it once on Rachel’s show, and it was everywhere the next day. It was up on Web sites, people were e-mailing me — that, for me, was a really clear indication of how powerful television is.”