From a story on politico.com by Jeff Greenfield headlined “Biden Lacks the Best Weapon Other Incumbents Have Had”:

Those New York Times polls showing President Joe Biden trailing in almost every key state surely spiked Maalox sales among Democrats; they led former Barack Obama advisor David Axelrod to suggest that the president might take a look at the “EXIT” signs at his campaign headquarters.

Some Biden supporters and sympathetic analysts tried to dismiss the polls, noting Election Day is still a year away. There’s a whole campaign to run, after all. But the truth is, Biden faces a difficult hurdle that previous embattled incumbents never had to contend with: a sharply diminished chance to “define” the opponent.