It’s better than Mitt Romney’s 12-point victory with that group in the state in 2012, according to Upshot estimates. Mr. Trump appears to be especially strong in northeastern Pennsylvania, including the Scranton and Wilkes-Barre area, where Mr. Trump leads by 16 points. Mr. Romney won the region by four points in 2012.

But these gains would not be sufficient for Mr. Trump to win the state, even if he matched Mr. Romney’s standing among other voters — something he is not pulling off…

Mr. Trump has claimed in recent weeks that the election might be rigged because of fraudulent voting in Philadelphia. There is no evidence to support his assertion, but the poll suggests that the Democrats will again pull off a huge victory in the city. Mrs. Clinton has a 77-9 lead in Philadelphia, putting her on track to approach or exceed President Obama’s 85-14 percent margin from 2012.

Mrs. Clinton’s 90-1 lead among black voters suggests she could win a unanimous share of the vote in some precincts in west and north Philadelphia. No black respondent from Philadelphia supported Mr. Trump in the survey.