Gingrich said on "Fox News Sunday" that while Romney leads the delegate count, his bandwagon could sputter at any time and open the door for his competitors.
"Yes, he [Romney] is a front-runner, but he is not a very strong front-runner," said Gingrich. "Almost all conservatives are opposed [to him], which is the base of the party."
Gingrich said Romney was not steamrolling his way through the primary states and scoffed at the idea that he drop out of the race and back Romney. "The Mitt Romney camp has been trying to sell since last June that I should get out of the race and that Romney is inevitable," Gingrich said. "But the fact is, Romney is probably weakest Republican front-runner since Leonard Wood in 1920."
Wood, a retired U.S. Army general, won the New Hampshire primary in 1920 but lost the GOP nomination to Warren G. Harding at the party convention
Gingrich said his campaign was in good shape heading into the 2012 convention and could make a move on Tuesday when primary votes take place in Alabama and Mississippi. "As almost everywhere, you start a little behind because of Romney's money and the length of time he's been advertising," he said. "As you campaign, you catch up with him pretty rapidly."
Notable deaths of 2014 [PHOTOS]