Public-opinion polls are a snapshot in time, and results can change quickly in politics as events intrude. But the polls have been sending Democrats and President Biden the same election warning for months, so perhaps they’ll eventually start listening.

The latest Siena College-New York Times poll of six battleground states, released on the weekend, is a five-alarm fire for Democrats a year before the election. It shows Mr. Biden losing to Donald Trump in five of six states on which the 2024 election is likely to hang.

Mr. Biden trails Mr. Trump by 10 points in Nevada, six in Georgia, five in Arizona and Michigan, and four in Pennsylvania. He leads only in Wisconsin in the survey, and there by two points. Those are awful numbers for an incumbent and would add up to more than 300 votes in the Electoral College. Numbers like that could help the GOP pick up Senate seats in Michigan, Pennsylvania and Arizona.

Especially striking is that Mr. Biden does worse than even Vice President Kamala Harris against Mr. Trump. A generic, unnamed Democrat leads Mr. Trump by eight points. This suggests voters have soured on Mr. Biden in particular, and the survey shows 71% of voters think he is too old to run again, including 51% of Democrats.

The usual caveats apply. The election is still a year away, and Mr. Trump has benefited from his relative lack of exposure while being out of office. As voters focus on the election next year, Mr. Trump’s manifest liabilities will reassert themselves. And that’s before his three criminal trials play out, two of which are scheduled for the first half of next year.

But the results in survey after survey show that Mr. Biden is in perilous re-election shape. His Bidenomics pitch hasn’t worked as voters remain sore about rising prices and a fall in real wages during his Presidency. His age and carriage are huge weaknesses even against the 77-year-old Mr. Trump.

The war in the Middle East is now dividing Mr. Biden’s coalition, as anti-Israel progressives turn on the President. We think Mr. Biden deserves credit for supporting Israel, and so do most Democrats. But in a closely divided country, even a small defection by a core group of voters can turn a swing state.

All of this should be cause for soul-searching in the Oval Office and with Jill Biden in the private White House residence. There’s a compelling case that Mr. Biden can best help his party, and the country, by announcing he won’t run again. He can say he wants to focus on helping Ukraine and Israel defend themselves against Russia and terrorist militias, and let younger Democrats take on Mr. Trump.

In 2020 Mr. Biden won as the Democrat most likely to beat Mr. Trump, and he did. But he now risks squandering that legacy by losing to Mr. Trump in a rematch. Mr. Biden surely doesn’t want to go down in history as the Democrat who overstayed his welcome and restored Donald Trump to power.

This editorial first appeared in The Wall Street Journal on November 5, 2023. It was distributed by The Associated Press.