This is the second national poll I have seen in the past few days that show Sanders ties with or leading Biden by a point. Keep in mind it is very possible Sanders wins both Iowa and New Hampshire which traditionally boosts the candidate throughout the primary.
On a side not it is interesting Bloomberg is up to 9% not have even participated in the debates.
Reuters/Ipsos national poll
I realize other polls have Biden up but with the Iowa caucus two weeks away people need to entertain the thought Bernie Sanders could be the Democratic presidential nominee.