The Democratic convention in Chicago is fast approaching - the moment when Kamala Harris is due to be officially confirmed as the party’s nominee to replace President Biden. So we're asking how this dramatic change at the top of the ticket has impacted polling ahead of November’s election. What do the numbers tell us in the crucial swing states, and which issues will move the dial for the voters who could tip the balance in the race against Donald Trump? On this episode, Sumi Somaskanda is joined by Courtney Subramanian from the BBC’s digital team in Washington DC and Eli Yokley, US politics analyst at polling firm Morning Consult. The Global Story brings you trusted insights from BBC journalists worldwide. We want your ideas, stories and experiences to help us understand and tell #TheGlobalStory. Email us at theglobalstory@bbc.com You can also message us or leave a voice note via WhatsApp on +44 330 123 9480. This episode was made by Laurie Kalus and Tom Kavanagh. The technical producers were Jonny Hall and Gareth Jones. The assistant editor is Sergi Forcada Freixas and the senior news editor is Richard Fenton-Smith.