A poll released today by Public Policy Polling, a firm associated with Democrats, reports that incumbent Democrat Sen. Jon Tester leads Republican challenger Rep. Denny Rehberg 48–43 percent with nine percent undecided.
The poll assumed a two-man matchup, sampled 934 Montanans but only 332 “usual Democratic primary voters.” The sampling margin of error at the 95 percent confidence level is 3.2 percent for the full sample, and 5.4 percent for the sample of Democrats.
In the Democratic primary for the U.S. House, Gillan leads Smith by eight percent, Wilmer by 10 percent, and the rest of the field by a lot more.
First caveat. Thirty percent of the sample identified as Democrats, 33 percent as Republicans, and 37 percent as Independents. That’s misleading. Most research shows that only 10 percent or so are true independents. The rest of self-identified independents are closet partisans whose affiliation can be determined by asking whether they lean Democrat or Republican. It looks as though this poll omitted that step.
Second caveat is that thanks to penny-pinching by Montana Secretary of State Linda McCulloch, two Libertarian Party candidates will be on the ballot for Senate in the general election. Their share will come out of the undecideds’ total, which could work to Rehberg’s disadvantage as it did to Burns’ disadvantage in 2006.