Polling suggests Trump is poised to win key battleground state

If past is prologue, Donald Trump will win Pennsylvania.

Eight years ago this week, Hillary Clinton led in Pennsylvania by more than nine points; four years ago, Joe Biden led by nearly six points. Clinton lost Pennsylvania by less than a point, while Biden won it by more than a point.

Heading into the Democratic National Convention, the Emerson/RealClearPennsylvania poll showed Trump leading Vice President Kamala Harris by a point.

Averaging together the Pennsylvania polling...