...As evidence of Mr. Clinton's impact, the campaign cites the Pennsylvania primary, which Sen. Clinton won by a margin of nearly 10 percentage points over Sen. Obama. Campaign data show that Sen. Clinton won by huge margins in several rural counties that her husband visited: 44 percentage points in Armstrong County, 44 points in Cambria County, 48 points in Carbon County and 50 points in Greene County. This compares with an edge of 26 points for Hillary among rural voters statewide. In Bucks County, a Philadelphia suburb that Mr. Clinton visited, Sen. Clinton won by 26 points, compared with only...