After a poor debate performance unleashed weeks of pressure, President Joe Biden announced on Sunday that he was ending his campaign for reelection and endorsing Vice President Kamala Harris to succeed him. The process was agonizing and it’s not immediately clear if endorsements from Biden and scores of Democratic politicians, as well as numerous convention delegations, will be enough to clear the field for Harris. [time-brightcove not-tgx=”true”] The difficulty of orchestrating the situation reflects a process that developed in the late 1960s and early 1970s.