MILWAUKEE (CN) – A poll released Thursday shows Vermont Senator Bernie Sanders with a double-digit lead over his fellow Democratic presidential candidates in Wisconsin, indicating the front-runner’s recent surge extends to the crucial battleground state.

The poll conducted by Marquette University Law School from Feb. 19 to 23 showed that 29% of Wisconsinites surveyed answered that Sanders is their first choice of the Democratic presidential hopefuls, with 13% saying the Vermont senator is their second choice.

Former New York City Mayor Michael Bloomberg came in a distant second at 17%, followed by former Vice President Joe Biden with 15% support and former South Bend Mayor Pete Buttigieg at 13%. Minnesota Senator Amy Klobuchar and Massachusetts Senator Elizabeth Warren trailed with 11% and 9% support among voters, respectively.

Sanders saw a 10% jump in support since January, when a Marquette poll showed he was the first choice of 19% of registered voters, meaning the Sanders campaign’s runaway energy since winning or tying for first in the first three Democratic primaries in Iowa, New Hampshire and Nevada is translating to support in the Badger State, which will prove to be a key battleground in the November general election.

Sanders cruised to victory in Wisconsin’s 2016 Democratic primary, besting Hillary Clinton by 13 points with 56% of the vote and taking 10 more delegates in the state.

Conversely, Biden’s support among Wisconsin voters has halved since November, plummeting from 30% in the fall to 15% this month. Sanders polled at 17% in the November poll.

The survey showed that Wisconsinites have become surer of their choice since that time as well. Forty-two percent of voters say their mind is made up compared to 37% in November, but 56% still say they might change their mind before the election, compared to 62% who felt that way in the fall.

When asked about favorability, Sanders prevailed among the six Democratic candidates in Thursday’s poll with 62% viewing him favorably. Biden, Warren and Buttigieg took the next three spots in terms of favorability at 61%, 56% and 52%, respectively.

Bloomberg, who has been flooding the Wisconsin and nationwide airwaves with millions of dollars in advertisements since his late entry into the race in November, is the only candidate viewed more unfavorable than favorable in the poll, with 37% viewing him unfavorably and 35% viewing him favorably.

Sanders also did better than other Democrats among voters who consider themselves either liberal or very liberal and voters who consider themselves moderate or conservative. Twenty-two percent of moderate or conservative voters said they would choose Sanders first, compared to 20% for Biden and Bloomberg in second place. Sanders clobbered the Democratic field among liberal or very liberal voters with 37% as compared to the second-place candidate, Buttigieg, with 12%.

The Vermont senator is also the only Democrat in the poll that would beat President Donald Trump in a head-to-head matchup in Wisconsin, according to the poll, topping Trump 48% to 46%.

However, Wisconsinites’ support for Trump appeared to be unabated, as 48% of respondents approved of his job performance compared to the same number who said they disapprove. This is the first time Trump’s disapproval numbers have been the same or lower than his approval numbers in Wisconsin since the first such poll was conducted in March 2017.

Views on the president remain starkly partisan in the state, as 95% of Republicans polled say they approve of Trump’s job performance against 4% who disapprove, and 93% of Democrats said they disapprove compared to 6% who approve.

Marquette’s survey polled 1,000 registered voters in Wisconsin over the phone and has a margin of error of plus or minus 3.6%.