Both Biden and Sanders polled well ahead of other contenders, like Elizabeth Warren at 14 percent and Pete Buttigieg at 11 percent. Michael Bloomberg’s support was at 5 percent.

Sanders and Warren have been tagged as the progressives in the group, and recent tensions have created a divide between their supporters. Warren accused Sanders of saying a woman couldn’t win the 2020 presidential race in a private 2018 meeting, and Sanders has vehemently denied the claim. Sharp attacks also recently came from Sanders’ 2016 opponent, Hillary Clinton, who called Sanders a “career politician” whom “nobody likes” in a forthcoming documentary.

Despite the controversy, Sanders has maintained consistent enthusiasm among voters since last fall. In the new CNN poll, 38 percent of Democratic voters said they would be enthusiastic if Sanders were to win the nomination, marking just a 1 point dip from October, whereas voters’ enthusiasm for Warren as the potential nominee has fallen 12 points to 29 percent. Biden’s dropped 9 points to 34 percent.

Biden is still polling highest at 45 percent with the perceived best chance to beat President Donald Trump in 2020. Sanders at 24 percent saw an 8-point increase since last month’s poll.

Trump has fixated on Sanders’ campaign in recent weeks, accusing Democrats of trying to sabotage his presidential bid by pulling Sanders out of Iowa during impeachment proceedings and unfairly attacking him.

“They are taking the nomination away from Bernie for a second time. Rigged!” the president tweeted Wednesday morning.

