Bill Clinton's post-presidential journey: a story told in convention speeches

Former President Bill Clinton is preparing to deliver his 12th address to the Democratic National Convention. Clinton speaks Wednesday night, facing uncertainty about the impact he'll have on a party that is trying to prevent Donald Trump's return to the White House. Clinton's political journey can be traced in part through his evolving role at Democratic conventions over the years. His appearances include a 1988 speech that went long and became the butt of jokes, and a 2012 speech aiding Barack Obama that earned Clinton the nickname the “secretary of explaining stuff.”