Richard M. Daley spent 21 years as Chicago's mayor before announcing that he would not seek re-election. His father Richard J. Daley also spent 21 years in the same job but died there. Some thought the younger Daley would do the same until his surprising declaration. Together, the pair leave a mighty urban legacy. Richard J. was the archetypal machine pol, who ruled the ethnically fractious city with an iron fist from the 1950s through the '70s. Although tough and sometimes imperious like his dad, the son had a more ambitious vision--guiding Chicago into a cosmopolitan future through support for the arts and development projects like the grand Millennium Park. He also oversaw bold school reforms and tore down some of the city's most notorious housing projects. But personal and political matters have weighed on Daley. His wife Maggie is battling cancer. And hard economic times have taken a toll: although Daley was last re-elected with 71% of the vote, a July poll found that just 31% of voters would select him again. In today's political environment, even an incumbent whose family name carries 42 years of political lore isn't safe anymore.