Penny Pritzker

AGE: 52
OCCUPATION: Founder and CEO, Pritzker Realty Group; philanthropist and investor

Penny may not be as rich as her brother J.B. (No. 20), though her reported $1.7 billion net worth is nothing to sneeze at, and she may not run a business as big as Hyatt, like her cousin Tom (No. 37). But when you want to make something happen in Chicago—whether to get your candidate elected or to get attention for your cause—you want Penny in your corner. She not only wheels and deals in real estate (her stake in a string of luxury retirement communities she cofounded recently sold for $478 million), but she’s on the boards of Chicago Public Schools, TransUnion, Hyatt, and countless nonprofits and is a conduit for Obama’s campaign donations.

MORE ON PRITZKER: A Brief Who's Who of Early Obama Donors | Our 2002 profile of the Pritzker dynasty

RELATED: Most Powerful Ex-Chicagoans | Power Couples | Power Siblings | Up-and-Comers | Poll: Which Powerful Chicagoan Would You Call Back First? | Quiz: Do You Know Chicago’s Power Players? | Back to all 100