DUBUQUE, Iowa — Dr. Jack Dolehide remembers the trinity on display in his boyhood home in Chicago in the 1960s: There, in the center, was an iconic image of Jesus. On one side, Mayor Richard J. Daley, the city's legendary Democratic boss. On the other, President Kennedy.

Then one day about 1969 or '70, the unthinkable occurred. Dolehide's father took down the politicians' portraits, ripped them into pieces and threw them away. He had become a Republican.