Popper is a member of the Libertarian Party, and has previously expressed support for the Republican Party. He endorsed George W. Bush in the 2004 U.S. presidential election. In November 2008, Popper said, regarding Barack Obama, "this is the first time I've voted for a Democrat, ever." John Popper was a supporter of Ron Paul during the 2012 U.S. Presidential election, even participating in phone-banking at Ron Paul's New Hampshire campaign headquarters. He also played a short set during Ron Paul's "We are the Future Rally," an alternative convention for Paul supporters which was held in Tampa the day before the 2012 Republican National Convention.