สีสีนการประชุมใหญ่พรรคเดโมแครตวันที่ 4: Democratic National Convention

Hillary Clinton formally accepts the Democratic Party's nomination for President on the fourth night of the Democratic National Convention in Philadelphia, July 28, 2016. (A. Shaker/VOA)

Hillary Clinton and Bernie Sanders supporters hold dueling signs on the fourth night of the Democratic National Convention in Philadelphia, July 28, 2016. (A. Shaker/VOA)

Chelsea Clinton introduces her mother, Hillary Clinton, on the final night of the Democratic National Convention in Philadelphia, July 28, 2016. (A. Shaker, VOA)

Delegates on the floor of the Democratic National Convention cheer ahead of Hillary Clinton's acceptance speech on the final night at the Wells Fargo Arena, July 28, 2016. (A. Shaker/VOA)

The Wells Fargo Arena in Philadelphia was packed on the final night of the Democratic National Convention, July 28, 2016. (Satarupa Barua/VOA)

Katy Perry sings to the Democratic National Convention in Philadelphia, July 28, 2016. (A. Shaker/VOA)

More supporters and delegates cheering early in the fourth night of the Democratic National Convention in Philadelphia, July 28, 2016. (Satarupa Barua/VOA)

An American flag waves at the Wells Fargo Arena in Philadelphia on the final night of the Democratic National Convention, July 28, 2016. (A. Shaker/VOA)

Nancy Pelosi addresses the fourth night of the Democratic National Convention in Philadelphia, July 28, 2016. (A. Shaker/VOA)

Democratic delegates cheer from the floor of the Democratic National Convention, July 28, 2016. (A. Shaker/VOA)