Senators Elizabeth Warren, Kamala Harris and Bernie Sanders drew large crowds at the Iowa State Fair in recent days, while lower-polling candidates struggled to generate attention in the crowded 2020 Democratic primary field. Former Vice President Joe Biden, the frontrunner, also received a warm reception from voters, but ended up being criticized for committing several gaffes.

Despite his stumbles, Biden has retained a comfortable lead in the polls as the primary season rolls on. But Biden's performance in Iowa did little to quell concern on the left about his chances of beating President Donald Trump in a general election showdown.

Tamara Keith of NPR and Shawna Thomas of Vice News are on hand to examine how the 2020 primary field navigated the Iowa State Fair. It's Politics Monday: Their expert analysis is one click away!