By Jim Ellis
May 22, 2017 — Early in this election cycle we’ve already seen several special and odd-numbered year campaigns produce conflicting polling data, and at the end of last week, a new example came forth. Two new polls from the Virginia governor’s race, Democratic primary, produced opposite results and both can be questioned in terms of reliability.
Earlier in the week, the Virginia Education Association released a Public Policy Polling survey (May 9-10; 745 likely Virginia Democratic primary voters), which projects Lt. Gov. Ralph Northam leading former US Rep. Tom Perriello (D-Charlottesville) by a substantial 45-35 percent margin.
Late last week, the Washington Post and the Schar School of George Mason University released their sponsored Abt Associates poll (May 9-14; 1,604 Virginia adults; 351 likely Democratic primary voters; 264 likely Republican primary voters) that produced a much different result. According to this polling sample, it is Perriello who actually holds a 40-38 percent preference lead among the most likely June 13 Democratic primary voters.
Not only do we see inconsistent conclusions from this pair of surveys, but also methodological questions arise. The Public Policy Polling survey has the stronger sampling group particulars, but may have bias problems. PPP features a robust sample of 745 Democratic primary voter respondents but the poll was conducted for an organization that is outwardly supporting Northam, and the 10-point advantage for their candidate is beyond any previously released independent figures.