Polls May Shape Biden’s Future. Are They Up to the Job?

President Biden’s re-election campaign is in jeopardy because of his poor debate performance. But lurking behind the Democratic anxiety is another factor: the polls.

The average of polls has shown Donald J. Trump with an almost uninterrupted lead for 10 months, and this undoubtedly shapes the calculation of Democrats in Washington. It’s hard to believe there would be any serious drive to replace Mr. Biden if the polls showed him clearly leading, as they did throughout the last election.

This puts a big responsibility on polls and pollsters. The fate of the president may not rest in their hands, but — at the very least — it will be influenced by their methods. In a sense, it is what polling is supposed to do in a democracy: give political actors insight into the will of the people, enabling decision makers to better respond to the demands of the electorate.

At the same time, it’s not obvious that polling is up to the challenge.

Polls are inherently imprecise measurements, subject to countless sources of uncertainty. While they continue to be the best way — or only way — to measure public opinion in a big, diverse country, polls have been wrong before, and they will be wrong again.

And at this stage, Mr. Biden’s chances increasingly rely on the possibility that the polls are simply “wrong.” He could retake the lead in the polling before November, of course, but given the stability in the polls so far, it may be unrealistic to expect such a pronounced shift toward him.

Mr. Biden himself appears to be counting on the polls being “wrong.” In his interview with George Stephanopoulos of ABC last week, he questioned whether polling was “as accurate as it used to be.”