WASHINGTON — Democrats announced Tuesday that they will hold their party’s 2024 national convention in Chicago, choosing the biggest liberal city in the Midwest as they try to keep the momentum going after a strong midterm election performance in the key battleground region.Organizers from Chicago, Atlanta and New York spent months lobbying to be the site of the convention, but the final decision lay with President Joe Biden, who is expected to formally launch his reelection campaign in the coming weeks.&ldquo …