Right now, many of the Democratic primary candidates are traveling through Iowa, shaking hands with voters as they make their way to the Iowa State Fair. In the coming days, just about every candidate running for president will stop by the Des Moines Register soapbox to give a stump speech.

In this installment of the FiveThirtyEight Politics podcast, Galen speaks with Ann Selzer, who conducts the Iowa Poll for the Register and whom FiveThirtyEight has called “the best pollster in politics.” The two discuss trends in Iowa polling and how the Iowa Democratic Party’s changes to the caucuses might affect who gets the nomination in 2020.

You can listen to the episode by clicking the “play” button in the audio player above or by downloading it in iTunes, the ESPN App or your favorite podcast platform. If you are new to podcasts, learn how to listen.

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