A new Gallup poll of Republican registered voters' predictions of who will ultimately win the 2012 GOP presidential nomination confirms the rapid rise of Newt Gingrich.

The Dec. 1-5 survey, which included results from 1,227 Republicans and Republican-leaning independents who are registered to vote, found Mitt Romney in front, but by a slim margin compared to one month ago. This month 39 percent of responders predicted Romney will win the nomination, with 35 percent selecting Gingrich.

In the same poll last month, Romney obtained 47 percent while Gingrich sat at 4 percent.

With the end of Herman Cain’s campaign and the slow demise of Rick Perry, the new poll suggests the GOP race has two clear front runners. The timing of Gingrich’s surge comes just one month before the Iowa and New Hampshire primary votes. It poses the most serious challenge yet to Romney's bid.