Bernie Sanders is having a huge surge. The national average shows the gap between Biden and Sanders closing significantly.
The average for Iowa shows Sanders leading (i believe within the margin of error).
The average for New Hampshire shows sanders really leading.
There hasn't been much polling for Nevada lately, but the 2 done in early January (before his big surge) show biden and sanders almost statistically tied with 1 point and 5 points between them.
Sanders is well placed to win 2 or even 3 of the first 4 states.