Frida Garza

In his 2008 presidential bid, Barack Obama, then a US senator from Illinois, used the Internet to catapult himself onto the national scene—and changed political campaigning in the process. Deep into his second term in the White House, he is still using the web in groundbreaking ways for a world leader. Take, for example, the questions he has been fielding about the Iran nuclear deal on Quora, the insider question-and-answer site.