Democratic Party leaders are publicly standing by President Joe Biden after a disjointed debate performance. But there’s plenty of private worry about whether the 81-year-old president is up to the job itself or the task of defeating Republican former President Donald Trump. Presidential campaign history offers Democrats lessons to consult. But none offer reasons for optimism. Presidents who still had to shore up their own party support and enthusiasm in an election year invariably did not win second terms. George H.W. Bush, Jimmy Carter and Gerald Ford all faced significant primary challenges and lost. Biden had no such challenge. But Lyndon Johnson faced falling popularity and opted in 1968 not to run. Democrats lost anyway.
