Democratic Convention - Day Four

A t-shirt being distributed at the Democratic National Convention advertises the television show 'House of Cards,' whose main character Frank Underwood is a politician from South Carolina who, through blackmail, violence and cunning, becomes president of the United States. The shirts were being given away for free in Philadelphia on July 28, 2016.

A police officer stands guard outside the Philadelphia Convention Center at the Democratic National Convention in Philadelphia on July 28, 2016. All week, thousands of police officers kept the city safe in the midst of tens of thousands of additional visitors, raucous protests and an oppressive heat wave.

A vendor sells campaign buttons outside the Democratic National Convention in Philadelphia on July 28, 2016.

Delegates, tourists and locals shop for lunch at the Reading Terminal Market across the street from the Democratic National Convention in downtown Philadelphia on July 28, 2016.

Delegates line up for shuttles to the Wells Fargo Center to attend the Democratic National Convention in Philadelphia on July 28, 2016.

Two delegates from Wisconsin make their way through the crowd at the Democratic National Convention in Philadelphia on July 28, 2016.

Delegates from Wisconsin listen to speakers at the Democratic National Convention in Philadelphia on July 28, 2016. The Wisconsin delegation was seated next to the South Carolina delegation in the Wells Fargo Center on the fourth day of the convention.

Texas Congressman Joaquin Castro addresses delegates at the Democratic National Convention in Philadelphia on July 28, 2016.

Television host Samantha Bee, left, films a segment at the Democratic National Convention in Philadelphia on July 28, 2016.

Mother Jones Washington Bureau Chief David Corn speaks with a reporter at the Democratic National Convention in Philadelphia on July 28, 2016. Corn broke the story of Mitt Romney's "47 percent" comments, caught on a secret videotape, during the 2012 presidential election.

Reporters watch Hillary Clinton accept the Democratic presidential nomination from inside the media center at the Democratic National Convention in Philadelphia on July 28, 2016.

Delegates head for the exits at the close of the Democratic National Convention in Philadelphia on July 28, 2016.