From Charles Franklin:
Now the key question is whether undecideds push her over a 10 point win, or whether increases in turnout by new "unlikely" voters raises Obama’s total.
…remember, since the polls don’t allocate undecided, both they and the trend estimates are leaving some 8 percent of voters on the table. They will go somewhere, and if they break disproportionately for Clinton you have a "huge win", while if they go overwhelmingly for Obama you have a nail biter or a dramatic come-from-behind win. In previous primaries, the "winner" has usually enjoyed a significant increase in support beyond what the last polls showed.
The Dish 