i m wolf blitzer, you re in the situation room. we re live here at constitution hall, here in the nation s capitol, where in just a little bit more than 24 hours, the republican presidential hopeful will face off for the first time in a major debate on national security, foreign affairs and the economy. he will be mod rating the event co-sponsored by the her kaj foundation and american enterprise institute. on the eve of this critical contest an eye-popping shift? the republican con taft. a new cnn poll just released minutes ago, shows newt gingrich on top of the republican pack for the first time. look at this wp 24% of republicans asked, if the former house speaker is their choice to be the presidential nominee, compared to mitt romney there is a dead heat, with gingrich and romney nationwide. other candidates, all in single digits. our chief political analyst, still at constitutional hall looking at numbers, gloria, gingrich is doing amazingly well. in several categories