Protesters have flooded Hong Kong’s airport, paralyzing operations and escalating tensions between the semiautonomous territory and Beijing. The protesters are trying to send a message to government officials — and to people in mainland China. Guest: Javier C. Hernández, a New York Times correspondent based in Beijing. For more information on today’s episode, visit nytimes.com/thedaily.  Background reading:Demonstrations led the airport, one of the world’s busiest, to suspend check-ins for two days in a row this week, causing hundreds of flight cancellations. On Wednesday, some protesters apologized for the disruption.The unrest is exposing the inherent conflict in Hong Kong’s political system since China reclaimed the territory from Britain in 1997: an effort to unite Beijing’s authoritarianism with civil liberties.Here’s a guide to what prompted the Hong Kong protests, and a look at how they have evolved.