Sanders now leads the field with 27 percent support from Democrats and Democratic-leaning independents, based on the CNN national poll released Wednesday.
Sanders’s support jumped 7 points since last month, placing him in a virtual tie for first with Biden, who is at 24 percent. Sanders’s 3-point lead is within the poll’s margin of error.
Biden’s support had dipped just 2 points since December.
Sanders has seen a fairly steady increase in support in the monthly CNN polls since August, when he registered at 15 percent. Biden had maintained a fairly steady lead over the last six months, starting at 29 percent in August, until this month’s poll when Sanders surged ahead.
The top two candidates have a significant lead over the rest of the field. Sen. Elizabeth Warren (D-Mass.) trailed Biden by 10 points, in third place with 14 percent. Warren’s support decreased 2 points since the December poll.
Pete Buttigieg trails her by 3 points at 11 percent, a 3-point uptick for the former South Bend, Ind., mayor since last month.
With just two weeks before the primary voting season begins in Iowa, no other candidates registered double-digit support in the new survey.
Former New York City Mayor Michael Bloomberg is at 5 percent, followed by Sen. Amy Klobuchar (D-Minn.) and Andrew Yang at 4 percent each. Tom Steyer is at 2 percent, and no other candidates are above 1 percent, based on the poll.
The poll surveyed 500 Democrats or Democratic-leaning independents. It was conducted between Jan. 16 and 19 and has a margin of error of 5.3 percentage points.