Liberal poll expert Nate Silver at FiveThirtyEight -- which is now hosted by the NYT -- says Pat Toomey has an 88 percent chance of winning Pa's open Senate seat this year. He has consistently led in the polls (another this morning put him 9 up on Joe Sestak) and the closer you get to November, the harder it is to close a gap that great.

Forthwith:

Of late, the source of the Democrats’ problems has not necessarily been in high-profile Senate races where the Republicans have nominated inexperienced but headline-grabbing candidates, like  Sharron Angle in Nevada and Rand Paul in Kentucky (although the model regards both Ms. Angle and Mr. Paul as slight favorites). Instead, it has been in traditional swing states like  Missouri, New Hampshire, Ohio and Pennsylvania. The last time the Democratic nominee in Ohio, Lee Fisher, held the lead in any state poll, for example, was in June. Representative Joe Sestak, the Democratic nominee in Pennsylvania, has not led any poll there since May, and Robin Carnahan of Missouri has not held a lead since January. The Democratic nominee in New Hampshire, Representative Paul W. Hodes, has not led in any of 17 public polls in New Hampshire against his likely Republican opponent, Kelly Ayotte.

The Democratic candidate lags by single digits in each of these states, and victories there remain entirely possible (perhaps especially so in New Hampshire, where the Republicans have yet to hold their primary). But, at a time when they need to be drawing closer to their opponents as the clock ticks toward Nov. 2, these Democrats instead find themselves falling somewhat further behind. We are now close enough to Election Day that a deficit of as few as 5 percentage points may be difficult to overcome, especially in races where relatively few undecided voters remain.