Cory Booker
Age: 41
Occupation: Mayor of Newark, N.J.
Previous TIME 100 appearances: 0
Mayor Cory Booker isn't afraid to do some heavy lifting. When a snowstorm blanketed Newark, N.J., during the 2010 holiday season, he took matters into his own hands, shoveling streets with his staff and turning his popular Twitter feed into a help hotline. His efforts made the already popular mayor a social-media superhero. He has more than 1 million followers on Twitter, though Newark has just 280,000 residents. The attention was nothing new for Booker. Since his election in 2006 (when he won 72% of the vote), he has worked to create summer jobs for teens and help newly released felons find work. His efforts to revamp the city's police department — often cited as his biggest achievement — have lowered crime in Newark by more than 20%. Booker's next target? Newark's long-troubled school system. And for that seemingly intractable problem, he is getting some big-time help. After meeting Booker at a conference last July, Facebook CEO Mark Zuckerberg said he thought, "This is the guy I want to invest in. This is a real person who can create this change." A few months later, Zuckerberg handed over $100 million to help the city's schools — with the caveat that Booker head the initiative.