AGE: 39
OCCUPATION: Washington, D.C., schools chancellor
PREVIOUS APPEARANCES ON THE TIME 100: 0
PRO: Her education-reform efforts — including cracking down on tenure, closing failed schools and firing underperforming staffers — have earned Rhee bipartisan praise and a swell of enthusiastic supporters (dubbed "Rhee-bots").
CON: She's constantly (and sometimes noisily) sparring with teachers' unions and parents.