Age: 47
Occupation: Media celebrity, potential presidential candidate
Previous TIME 100 appearances: 2
There have been times in the past 2½ years when Sarah Palin's political stock was higher, but she's still the Republican Party's most dynamic and divisive power player. With two best-selling books and a full slate of winning candidates she endorsed in last year's midterm elections, the former Alaska governor and vice-presidential candidate holds the answer to perhaps the biggest political question of 2011: Will Sarah Palin run for President? Her entrance into a relatively sparse field could upend the contest for the Republican nomination. Candidate or not, Palin's mastery of social media and identity politics ensure that whatever she's doing, her party and the media will take note.