Let’s just say Tom Emmer’s day ended better than it started.
In the morning, MPR released a Humphrey Institute poll showing DFL Mark Dayton leading Republican Emmer 41 percent to 29 percent. But KSTP’s 10 p.m. news featured a SurveyUSA poll that showed Dayton leading Emmer by just 1 point, 39-38. Tom Horner has 13 percent.
Dayton’s lead is within any margin of sampling error. The 624-likely-voter poll was conducted Sunday through Wednesday.
The SUSA survey — which included cell-phone-only (CPO) voters for the first time — was sweet vindication for the Emmer campaign, which released an internal poll during the day showing the race tied 40-40.
Unlike the Humphrey Institute poll, where the partisan breakdown was 45 Democrat, 39 Republican, SUSA had more Rs than Ds: 35-33, with 33 percent independents. Horner took slightly more Democratic votes (13 percent) than Republican (11 percent).
The SUSA poll also had a 50-50 male-female breakdown. In 2008, women voters outnumbered men 53-47, the same split in the MPR/HHH poll. Still, it’s not a fixed number. As usual, women favored the Democrat (42-35 Dayton) and men the Republican (42-36 Emmer).
The CPO factor — which required the robo-polling SUSA to use live operators — didn’t really move the needle: Dayton and Emmer tied 35-35.
Although CPOs now represent 25 percent of households, they made up only 15 percent of SUSA’s sample. That’s reasonable, since CPOs are typically younger and less likely to vote.
A couple of SUSA surveys in other states also showed no real difference when CPOs were added. The Star Tribune’s pollster has Dayton picking up 5 points this summer from CPOs; nationally, Democrats pick up 0 to 4 points. In SUSA’s case, they were 2 points more pro-Emmer than land line voters.
On the newscast, KSTP’s Tom Hauser touted FiveThirtyEight.com’s high pollster rating for SUSA. However, on Thursday, FiveThirtyEight’s Nate Silver wrote that automated polls such as SUSA’s have a Republican “house effect” — in SUSA’s case, 4 points Republican.
Silver notes that “house effect” is only in relation to other polls. Polls that use exclusively human interviewers, like the Strib’s and MPR’s, are on the Democratic side of the ledger. Silver says his model splits the difference, but one side might be right.
The Minnesota history of SUSA final polls offers something for partisans of either stripe.
SUSA has recently underestimated Democratic margins by 5 to 7 points. The pollster gave Barack Obama a 3-point Minnesota margin in the 2008 presidential race; he won by 10. In the 2006 U.S. Senate race, SUSA had Amy Klobuchar up 16; she won by 21. And in the 2008 U.S. Senate race, the pollster gave Norm Coleman a 5-point lead; that was a dead heat.
On the flip side, SUSA nailed the last Minnesota governor’s race. The pollster had Tim Pawlenty and Mike Hatch tied in 2006. Pawlenty squeaked out a 1-point win.