I get this question a lot: are right-wing pollsters flooding the zone? So I thought I would answer it generally in a single post.
Are they? Yes, they definitely are. But there are some important caveats and qualifiers to know to make sense of the whole story.
Just to review the basics: There are a series of Republican or right-wing pollsters who are overtly partisan, use questionable or floating methodologies and pretty clearly release polls not as a predictive enterprise but to produce friendly numbers for Republican candidates. The worst offenders are places like Rasmussen, Trafalgar, InsiderAdvantage. We know this from a mix of a lack of transparency about methodology, general behavior that betrays a goal of shaping election perceptions and outcomes rather than measuring public opinion, and extreme “house effects” — the tendency to favor a particular party’s candidates over the other’s relative to what most pollsters are finding — that support their agenda. After those, there’s a larger penumbra of often less-known pollsters who don’t appear to be as flagrant, but generally seem to be in the same category.