VOA慢速英语:How America Elects Its President

shrinking – adj. smaller number

battleground – adj. states with very hard fought elections

barrage – n. a great amount of something that comes quickly and continuously

knock – v. to hit something (such as a door) with the knuckles of your hand or with a hard object

disenfranchise – v. to prevent a person or group of people from having the right to vote

petition – n. a written document that people sign to show that they want a person or organization to do or change something