While I often take polling with a giant grain of salt......OK, more like a block of salt (especially polls coming from a campaign) here is one from the Democrat running for US senate. Some of my big traditional discredits are samples not done on actual likely voters and ones done as a push poll (where the poll gives all the wonderful aspects of their candidate and none on the competition before asking
The below statement on the poll also came from the campaign.
The poll, conducted by Public Policy Poling (PPP) on behalf of the Adams for Senate campaign, sampled (n=531) likely Tennessee voters from December 2-3, including an oversample of Republican primary voters (N=391). The margin of error for the polls is +/- 4.3% for the general election sample and +/-5.0% for the Republican primary sample.
The Republican primary seemed to continue a trend of Tea Party candidates sneaking up on establishment Republicans. The Tea Party won surprising U.S. Senate victories in Texas, Florida, Delaware, Indiana, Utah, Missouri, Nevada and Colorado in the last two election cycles.
PPP is a leading national polling company and has conducted surveys since 2001 for political organizations, unions, and businesses. A Fordham University report released in 2012 ranked 28 organizations for polling accuracy - PPP was one of the most accurate pollsters.