The poll by Bloomberg has Sanders at 49% and Clinton at 48%. While that's well within the margin
|Sen. Bernie Sanders|
Clinton leads Sanders 1243-975 in pledged delegates. That is a margin that could be bridged especially in light of recent Sanders' momentum, as evidenced by landslide victories in five recent state caucuses. However, Clinton's commanding 469-29 lead in superdelegates makes it virtually impossible for Sanders to win. While the superdelegates could switch their allegiences, I think that is unlikely to happen.
For the record, I don't buy the Clinton talking point that she will be a better general election candidate than Sanders. Clinton's negatives are extraordinarily high (exceeded only by Republican Donald Trump) and every poll shows Sanders, not Clinton, the stronger candidate against the GOP in the fall.