With Iowa voters making their choice and the 2020 election getting underway, we’re introducing a new show: one covering the country and its voters in the lead up to Nov. 3. In our first episode of “The Field,” we ask Democratic caucusgoers how they’re feeling about the election. Traveling around the state, we found anxious Iowans asking one question over and over: Who can beat President Trump? Note: This episode contains strong language. Guests: Astead W. Herndon, who covers national politics for The New York Times, and Austin Mitchell and Andy Mills, producers for “The Daily.” For more information on today’s episode, visit nytimes.com/thedaily.  Background reading: Confused by the Iowa caucuses? Here’s how they work.The New York Times polled 584 Democrats likely to caucus in Iowa. Fifteen of them agreed to talk to us on camera. Here is what they told us.The state with a huge influence in picking presidential candidates doesn’t look much like the country as a whole, except in one very striking way: a rapidly aging population.