AGE: 58 OCCUPATION: President and CEO, Health Care Service Corporation

With health care costs zooming, the power to decide whether your doctor’s visit will be reimbursed is huge. And no single Chicagoan has more say on that than Hemingway Hall. She runs the company that owns the area’s biggest health insurer, Blue Cross and Blue Shield of Illinois. Should Obamacare withstand legal challenges, granting coverage to 1.75 million uninsured Illinoisans, her business can only expand.

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