Democratic Party officials this week are launching their in-person vetting of potential 2028 convention sites, with trips to the finalist cities — Atlanta, Boston, Chicago, Denver and Philadelphia. Why it matters: The Democratic National Convention is a crucial time for the party to reach a large national audience to make its case for retaking the White House in 2028 . Teams representing the contending cities already are knifing one another to try to land the event, which can bring prestige and an economic boost from tens of thousands of visitors. The intrigue: Each city has a team and outside allies trying to land the convention by promoting their city — and trying to undermine the others. Already, whisper campaigns are pointing out the potential flaws of each finalist: Atlanta doesn't have enough union hotels, Chicago hosted the convention in 2024, Boston signals "liberal elite," Denver isn't in a swing state — and Philadelphia, the 2016 host, is a reminder of the year Hillary Clinton lost the election.…