23 October 2018 — Updated 0952 mdt

MSU-MTN poll reports Tester has a 3-point lead on Rosendale

Updated. Sen. Jon Tester is leading his Republican opponent, state auditor Matt Rosendale, among registered voters by 3.1 points according to a poll conducted by Montana State University and released last night. The results:

Here’s the poll plotted on the template Flathead Memo will use for the rest of the election:

PDF for printing

The poll’s documentation does not indicate whether a likely voter screen was applied. Absent a explicit statement that a likely voter screen was applied, one must assume the poll reports the opinions of a sizable number of voters who will not vote. Generally, applying a likely voter screen weeds out more Democrats than Republicans. Therefore, Tester’s lead among likely voters might be less than 3.1 points.

Although the lead is small, it’s not a tie. According to the online calculator at the American Research Group, there’s a 91 percent probability that Tester has a ballot lead.

Questionnaires were mailed to 10,215 registered voters with valid addresses. The poll was open from 15 September to 6 October, and the response rate was 20.4 percent, with 2,079 questionnaires being returned. The margin of error was 2.1 percent.

Dr. David Parker of Montana State University’s political science department directed the poll. The methodology, crosstabs, and codebook, are available for download as PDFs at MSU’s HELPS Lab.

For additional information on how to interpret the margin of error and the probability of a ballot lead, please see yesterday’s post, It’s finger crossing time for Democrats.

The poll’s results for the Williams v. Gianforte election for Montana’s seat in the U.S. House of Representatives will be released this evening.