A new poll from NBC suggests that President Biden would lose a hypothetical general election matchup against President Trump, 46 percent to 44 percent. The president’s weakness comes from his lack of support among traditionally Democratic constituencies. 

Mr. Biden’s cratering poll numbers are due in part to his record on foreign policy, his handling of the economy, and his age. The president, who turns 81 on Monday, recently suffered a devastating poll result when the New York Times and Siena College performed a survey of six battleground states. In that poll, 71 percent said the president was “too old to be effective.” Among 18 to 29 year olds, 78 agreed with that statement. 

Among voters between the ages of 18 and 34, Mr. Biden’s approval in Sunday’s NBC poll has cratered and is now down to 31 percent from 46 percent in September. Overall, his disapproval rating is the lowest it’s been during his presidency.

Mr. Biden’s weakness in the new poll is due, in part, to Democrats and young people disapproving of the way he has supported Israel in its war against Hamas. Among those aged 18 to 34, a supermajority — 70 percent — disapprove of the way he is handling the war. 

Voters have long given Mr. Biden poor marks when it comes to his handling of the economy, but he did see a slight rebound on that score in this poll, with 38 percent saying they favor his economic agenda, up from 36 percent earlier this year. On foreign policy, though, Mr. Biden’s approval has only gone from bad to worse. Just 33 percent of voters approve of his foreign policy record, down from 41 percent in January. 

“Joe Biden is at a uniquely low point in his presidency, and a significant part of this, especially within the Biden coalition, is due to how Americans are viewing his foreign policy actions,” one of the people who conducted the NBC poll, Jeff Horwitt, said to the outlet. Mr. Horwitt’s polling partner, Bill McInturff, told NBC that, “This poll is a stunner, and it’s stunning because of the impact the Israel-Hamas war is having on Biden.”

The man who successfully managed President Obama’s 2012 reelection campaign, Jim Messina, said on X on Sunday that the poll is no reason for Democrats to start panicking given the election is still one year away and the Democrats’ ground game has yet to kick off in key states. 

“The only thing you can be sure of after today’s NBC poll is that people will short-circuit again,” Mr. Messina wrote. “Polls a year out are about as good at predicting election results as a magic 8 ball would be. They just don’t show the full picture. Team Biden needs to mobilize voters. Not be hyper-reactive and run the campaign Twitter tells it to.”

The president of the Democratic consulting firm Global Strategy Group, Jeffrey Pollack, also said it is not time for Democrats to begin setting themselves on fire. “Here we go again. Do I need to say it yet another time?” Mr. Pollack asked on X. “Replace name of poll to today’s NBC poll. Long time to go folks… see below. Tranquilo por favor.”

The NBC poll found that a majority of Democrats believe the Israeli military has been too aggressive in its counteroffensive at Gaza. In total, 51 percent say that Israel’s actions are not justified, compared to just 27 percent who believe the military actions are justified. 

The Israel–Hamas war has also been a political buoy for President Trump. In the wake of the war, Mr. Trump has, for the first time in NBC polling, overtaken Mr. Biden in 2024 general election polling. The former president leads the incumbent 46–44, which is within the margin of error. In June, the same NBC poll found Mr. Biden leading his predecessor by four percent. 

Mr. Trump also benefits somewhat from relatively strong support from groups that historically do not break for Republicans. Among those ages 18 to 34, Mr. Trump would win 42 percent, and among Black voters, Mr. Trump garners 20 percent of the vote. 

Mr. Trump, like Mr. Biden, is still no favorite of the general electorate. The NBC poll that Mr. Biden would lose decisively to a “generic Republican” by 11 percent, and Mr. Trump would lose to a “generic Democrat” by 6 percent.