Occupation: U.S. Senator from Connecticut
Previous TIME 100 Appearances: 0
Al Gore's former running mate turned John McCain endorser has redefined the term independent since losing the Democratic Connecticut primary in 2006. In the past year, he has called out President Obama on everything from sanctions on Iran to the Administration's growing army of czars. Yet Lieberman still caucuses with the Democrats, ultimately supporting health care reform, introducing legislation to repeal "Don't ask, don't tell" and spearheading talks on a global warming bill.