Gallup. January 15-19, 2012. Republican primary voters. ±4%. (Trends: 5-day rolling averages since December 1-5, 2011.)
In
the words of Frank Newport, Gallup's Editor-in-Chief: "Mitt Romney is a considerably weaker front-runner among Republican registered voters nationally than he was at the beginning of the week."
On Monday, his national lead was 23 points. Today, it's 10, and because Gallup's polling is a 5-day rolling average, it could very well continue to shrink—and perhaps disappear altogether assuming Newt Gingrich wins South Carolina. And remember, these results don't fully reflect last night's debate, during which Gingrich turned in another strong performance and Mitt Romney turned in perhaps his worst showing yet.
Even if you assume that Mitt Romney is still inevitable, these numbers are still pretty rough for him: I can't imagine a much more humiliating way to get the nomination. But a win is a win, I guess. Just ask Rick Santorum.