Until 1968, presidential candidates were picked by party conventions – a process revived by Biden’s withdrawal from race  The ConversationWhen is the DNC? Here’s what to know about 2024 convention after Biden drops out of race  USA TODAYWhat happens to Joe Biden’s Michigan delegates after he dropped out of presidential race  Detroit Free PressWhat Happens Next Now That Biden Has Dropped Out?  The Wall Street JournalTruman and Johnson Also Stepped Aside, but ‘the Circumstances Are Quite Different’  The New York Times