Age: 63
Occupation: Former U.S. President; founder of the William J. Clinton Foundation
Previous TIME 100 Appearances: 3
The former President still has enough global power and popularity that he can move the needle on a lot of matters: the fight against AIDS, a sticky diplomatic issue in North Korea, the rebuilding of postquake Haiti and the banning of soft drinks in public schools. It doesn't hurt that he's married to the Secretary of State.