It happens repeatedly in “Mr. Cao Goes to Washington,” an absorbing documentary that will be shown Saturday as part of the Boston Asian-American Film Festival, that the director cuts away while Anh “Joseph” Cao is still thinking about how to respond to an unanswerable question. Does he feel that he made the right choice in leaving the seminary to enter public life? How can a principled moderate succeed in a political climate dominated by extremists? Cao, a Vietnamese-American Republican from Louisiana who from 2008 to 2010 represented a heavily African-American and Democratic district in the House of Representatives, is an intensely reflective and articulate man. But these questions are stumpers.
Cao was elected because his opponent, William Jefferson, who would otherwise have won with ease, was caught red-handed in a major corruption scandal. African-American voters stayed home, and Cao eked out a win.