The trend graph for the Congressional Generic Ballot for 2010. As you can see, it moves along with the Republicans having a consistent but not dramatic advantage until about mid-summer. And then the red line just starts taking off …
Now many readers often ask how different the numbers would be without Rasmussen. And the answer is, in this case, not much.
At least for the moment, the GOP number is actually slightly better without the Rasmussen data set than with it. But overall, the story is that while Rasmussen was an outlier on the GOP side for most of the year, the trend is consistent with or without them — a GOP breakout around mid-summer.
There are a lot of potential points to make about these numbers. What stands out to me though is that the trends do not correlate with any of the major legislative events, for better or worse. But they do track pretty clearly with the stalling of the economic recovery over the last few months. As long as it seemed like the economy was making some progress, albeit very slow and probably not enough to keep the Dems from having a really tough mid-term, they were in the hunt. After the economy stalled, it all came apart.
Some of the difference over the last couple months has to do with pollsters either refining or applying their likely voter models. And that’s more an artifact of polling than a real change in the numbers. But if you look closely (for instance, the CNN poll just released still tracks ‘registereds’) that’s not what accounts for most of the movement.
