Sen. Bernie Sanders has a strong lead over his Democratic rivals among likely voters in Iowa, according to a new New York Times/Siena College poll released Saturday, just over a week out from the state’s caucuses.

The Vermont senator had the backing of 25 percent of respondents—a six-point surge since the Times-Siena poll from late October.

Support for Former Vice President Joe Biden and former South Bend, Indiana Mayor Pete Buttigieg is unchanged since the last poll, with Biden at 17 percent and Buttigieg at 18 percent in each.

Sen. Elizabeth Warren’s 15 percent put her in fourth place in the new poll, a drop from the 22 percent that put her at the top of the Demcratic pack in October.

Download the crosstabs from this morning’s NYT/Siena College Poll in Iowa (follow the link)! NY Times/Siena College Poll of Likely Iowa Democratic Caucus Participants – https://t.co/IsdJx3LPjl — SienaResearch (@SienaResearch) January 25, 2020

The support captured by Sanders from younger likely Iowa caucus goers blows away his rivals.

Sanders had 40 percent of support from those under 30. Warren and Buttigieg came in distant second for that age group, with each getting 16 percent. Biden had 10 percent, and no other candidate scraped double digits.

For those aged 30-44, Sanders was again in the lead with 31 percent. Trailing well behind at 19 percent, Warren and Buttigieg tied for second place, and Biden followed with 14 percent.

Biden bested his rivals with voters over 65, nabbing 32 percent with Buttigieg a distant second at 17 percent.

The survey of 584 voters was conducted Jan. 20-23 and has a margin of error of plus or minus 4.8 percentage points.

A possible factor in Sanders’ lead in the new poll, progressive journalists John Nichols and Krystal Ball suggested on Twitter, could be senator’s rejection of President Donald Trump’s march to war with Iran

Pundits have routinely underestimated how much voters care about issues of war and peace. https://t.co/bCAchOVUes — Krystal Ball (@krystalball) January 25, 2020

As the Times reported, “the race remains up for grabs” — 39 percent said they could be persuaded to caucus for a different candidate. Still, another good sign for Sanders’s supporters was the Iowa poll out earlier this month from Des Moines Register/CNN/Mediacom that put him in the lead with 20 percent, a five-point surge in support from November.

Sanders, on Twitter, said Saturday that it was not a moment for complacency.

“We’ve got a long way to go,” he said. “It’s going to be a tough fight and we can’t take anything for granted. Knock on doors. Make phone calls. Do everything you can.”

Iowa’s first-in-the-nation caucuses are Feb. 3.