Toomey needs to be in the position in which he looks to be in the lead with 44% or more. He should be well-enough known by now.
It probably represents a lack of excitement about the race and voter discontent with their choices. Plenty of dems still hold a grudge on Sestak for beating Specter six years ago, and McGinty is honestly a pretty pathetic anti-sestak. Meanwhile, Toomey probably angered some conservatives with his gun control stuff, and hasn't given Democrats anything particular to turn out against him en masse over - he's spent the last five years being decidedly boring and inoffensive on everything except gun control.
