A good point

(FirstRead) "...There's a pattern that ought to worry Obama: He is consistently sitting in the low 40s in the state(Pa.) In fact, his range is strikingly consistent, while Clinton's number is all over the map -- from the mid-40s to mid-50s. Does Obama have a ceiling in Pennsylvania? And does this mean a five-point lead for Clinton in these new polls today could quickly turn into a 15-point one if undecideds move en masse to Clinton?"