Three new polls out show Hillary Clinton maintaining or widening her lead against Barack Obama in anticipation of the Pennsylvania primary tomorrow.

Survey USA has Clinton leading by six points 50-44. This is down from a 14 point lead earlier. The Quinnipiac poll has Hillary up 7 51-44 while the Suffolk University poll has it 52-42 Clinton.

The significance here is that first of all, Hillary has cracked the all important 50% mark in all three polls - a gauge that pollsters use to measure strength.

But there is potential trouble for Clinton in the numbers detailing the white vote. Hillary needs a large turnout of whites and needs to win at least 58% - 60% of them to score a double digit win. This excellent analysis at Talk Left explains her problem:

Projecting the undecideds gets me to 54-46 Clinton. If Obama can capture 40% of the white vote, as Q seems to predict (and one assumes SUSA as well), then he can keep it under double digits.

That is the mystery in PA today. What will be Clinton's margin among white voters. Will it be 60-40 or 67-33 or what in between? Suffolk says Clinton by 10, 52-42. The Suffolk poll projects turnout to be 81% white, 14% A-A.

That means Clinton winning about 62% of the white vote by my calculation. In the end, a 60-40 split among whites means Clinton by 8. 67-33 means means Clinton by 16.

PPP predicts a 3 point Obama win. PPP believes white turnout will be very low, only 76% of the total and A-A turnout will be high, 18% of the turnout, 6% other (Latino?). PPP also believe Obama will only lose Whites by 52-38 (10% undecided).

If this result holds up, then this race is over.