Bernie Sanders at the National Motorcycle Museum in Anamosa, Iowa. Photo: Stephen Maturen/Getty Images

On Sunday, Bernie Sanders received good news after a holiday drought of polling data: According to a CBS News survey conducted by YouGov, the Vermont senator is leading the field by three points in New Hampshire, and is tied for first place in Iowa with Joe Biden and Pete Buttigieg, with 23 percent of support.

Sanders, who won New Hampshire in the 2016 primary, also has the sturdiest base of support among Democratic candidates in the two early states, according to the poll: 47 percent of his New Hampshire supporters and 43 percent of his Iowa supporters told CBS News that “they’ve definitely made up their minds.” In contrast, just 15 percent of Biden’s supporters in New Hampshire have made a steadfast choice. However, voters in both states do think that Biden is the most likely Democrat to defeat Trump: 38 percent of those polled in Iowa and 36 percent of those polled in New Hampshire consider the former vice-president the most electable candidate, compared to Sanders’s 29 percent and 33 percent.

The survey is less welcome news for the campaigns of Pete Buttigieg and Elizabeth Warren: In polling averages from late October through early December, Mayor Pete and the Massachusetts senator led the race in both states, with 21.4 percent to 19 percent support in Iowa, and 18.3 percent to 17.9 percent support in New Hampshire. Senator Amy Klobuchar fell short of the front-runners, but remains in the race with 7 percent support in both states in the CBS/YouGov poll.

Though Joe Biden leads polling nationally by almost ten points, Sanders’s current showing in New Hampshire and Iowa is bolstered by his strength in California, where he may be able to steal the lead away from Biden — Sanders is currently down 2.3 points — if his recent surge in the state and strong support among Hispanic voters continues.