I’ve given Public Policy Polling some grief about their polls, contending that because they don’t weight for party, many of their polls this year have presumed a throughly unrealistic level of turnout among Democrats.

Well, give them a bit of credit; they have now shifted from polling “registered voters” to “likely voters.” And the results are dramatic:

In PPP’s previous survey of the Pennsylvania Senate race in June, Republican Pat Toomey and Democrat Joe Sestak were dead even at 41% among occasional voters. In the first survey using its likely-voter model, however, PPP now finds Toomey jumping out to a 9-point lead, 45-36, with 20% still undecided.

Their release spends a paragraph trying to explain that they think their sample was too conservative.

Also noteworthy: President Obama’s approval/disapproval splits at 40/55 among likely voters in Pennsylvania.