With just two weeks left in the campaign, Mr. Trump does not hold an edge on any of the most pressing issues at stake in the election, leaving him with little room for a political recovery absent a calamitous misstep by Mr. Biden, the Democratic nominee, in the coming days. The president has even lost his longstanding advantage on economic matters: Voters are now evenly split on whether they have more trust in him or Mr. Biden to manage the economy.

On all other subjects tested in the poll, voters preferred Mr. Biden over Mr. Trump by modest or wide margins. Mr. Biden, the former vice president, is favored over Mr. Trump to lead on the coronavirus pandemic by 12 points, and voters trust Mr. Biden over Mr. Trump to choose Supreme Court justices and to maintain law and order by six-point margins. Americans see Mr. Biden as more capable of uniting the country by nearly 20 points.

Over all, Mr. Biden is backed by 50 percent of likely voters, the poll showed, compared with 41 percent for Mr. Trump and 3 percent divided among other candidates.