Single poll and all but those VA numbers really leap out at me because it should be a strong state for Biden.
Yeah I originally assumed the best Bernie could do on Super Tuesday was win California, Colorado, Maine, Massachusetts, Minnesota, Oklahoma, Utah and Vermont. Which would still be impressive! 8 out of 14, so he'd win more states, but my guiding assumption was Biden would smoke him in the remaining six states - Alabama, Arkansas, North Carolina, Tennessee, Texas and Virginia - and come out with a delegate lead.
That being said, since then I've felt Sanders has a real shot at flipping North Carolina, Texas and Virginia. And if his math is good enough to win there, he's probably winning the other eight states (with more favorable demographics) by wide margins.
Regardless of how the delegate math shakes out though, 18 states will have voted by Tuesday and Sanders may have won all but four of them. (I'm counting Iowa as a Sanders win on the grounds of the popular vote, in case anyone wants to be pedantic about Buttigieg winning the delegate count there) If that's the case Biden is going to be a very tough sell.