From a New York Times column by Ross Douthat headlined “Why Is Joe Biden So Unpopular?”:

Joe Biden is an unpopular president, and without some recovery, he could easily lose to Donald Trump in 2024.

By itself, this is no great wonder: His two predecessors were also unpopular at this stage of their presidencies, also endangered in their re-election bids.

But with Trump and Barack Obama, there were reasonably simple explanations. For Obama, it was the unemployment rate, 9.1 percent in September 2011, and the bruising battles over Obamacare. For Trump, it was the fact that he had never been popular, making bad approval ratings his presidency’s natural default.