John Powers

Two new documentaries probe the effects of outside influences on third-world countries. In Our Brand is Crisis, the arrival of U.S. campaign consultants threatens the outcome of a Bolivian presidential election. And Darwin's Nightmare is about the devastation of Lake Victoria in Tanzania.

Several recent DVD releases feature great black entertainers of the 20th century. For classical music critic Lloyd Schwartz, his favorites feature the great tap dance team of Harold and Fayard Nicholas.

Critic at large John Powers reviews the two-DVD edition of the 1939 classic film Young Mr. Lincoln, directed by John Ford and starring Henry Fonda.