Sen. Bernie Sanders has a commanding lead in his neighboring state of New Hampshire, according to twin polls fielded in the early voting state.

A quarter of likely Democratic primary voters in New Hampshire would cast their ballot on Feb. 11 for Sanders, up 4 percentage points since October, a CNN poll conducted with the University of New Hampshire found.

In the poll released Sunday morning, the socialist senator from Vermont, 78, has a 9 percentage point advantage on former Vice President Joe Biden's 16% support, as well as a sizable lead on former South Bend, Indiana, Mayor Pete Buttigieg's 15% and Massachusetts Sen. Elizabeth Warren's 12%. His rise in support comes at the expense of Warren, who has dropped 6 percentage points since last fall.

NBC News and Marist's first poll of New Hampshire also provided evidence of Sanders's popularity in the state, where he beat Hillary Clinton by more than 20 percentage points during the 2016 Democratic race for the White House. In that study, 22% of likely primary voters back him, followed by Buttigieg with 17%, Biden with 15%, and Warren with 13%.

The polls are a boost for Sanders a week out from the Iowa caucuses on Feb. 3, the opening contest to decide which candidate will become the 2020 Democratic presidential nominee. While the former Vermont congressman and mayor of Burlington has been a consistent front-runner since announcing his bid last February, his polling numbers were chalked up to name recognition until a slew of recent surveys of likely Iowa caucus-goers still had him on top with Biden.

The host of polls published this weekend were a boon for Andrew Yang as well. The entrepreneur, 45, has now qualified for the New Hampshire debate on Feb. 7.

"Thank you to everyone working hard to make it happen. Let’s make history," Yang tweeted Sunday.

Just qualified for the February debate in New Hampshire! Thank you to everyone working hard to make it happen. Let’s make history. 😀👍🇺🇸 @khrystinausa @marchandsteve https://t.co/5KGyFN5jBa — Andrew Yang🧢 (@AndrewYang) January 26, 2020

Pollsters for CNN and the University of New Hampshire interviewed 516 likely Democratic primary voters between Jan. 15 and Jan. 23. Their findings have a margin of error of plus or minus 4.3 percentage points. Meanwhile, NBC News and Marist spoke to 697 likely primary voters from Jan. 20 through Jan. 23 for results with a margin of error of plus or minus 4.5 percentage points.