Building a 'city within a city:' Behind the scenes of the CNN 2020 debate

CNNPolitics: More than 20 tons of gear. Hundreds of CNN employees. The stage of a 1920s theater where Elvis Presley once performed updated for a global television audience.
On screen, viewers at home will see 10 candidates -- 20 over the course of two nights -- make their case for why they should be the next President of the United States.