Former House Speaker Newt Gingrich’s (R-Ga.) electability against President Obama and authenticity as a conservative were in focus at the top of Thursday’s Republican presidential debate in Iowa, the last such skirmish before the state’s Jan. 3 caucuses.

Debate moderators informed Gingrich that he had been placed at the center of the stage for the Fox News debate because he was now the accepted front-runner, but that there were major concerns about whether he would be viable against Obama.

Gingrich, who frequently touts his experience as a historian, recalled the 1980 presidential contest and said that had the GOP prioritized electability above all else, they wouldn’t have nominated Ronald Reagan to run against President Jimmy Carter.

“He’s the person I want to have debate Jimmy Carter,” Gingrich said. “I believe I can debate Barack ObamaBarack Hussein ObamaJudge rules against Trump administration in teen pregnancy prevention case Parkland student rips Obama for essay on shooting survivors Obama pens Time 100 entry for Parkland survivors MORE, and I think in seven 3-hour debates, Barack Obama will not have a leg to stand on.”

Gingrich was also asked about those who have publicly doubted he is really as conservative as he maintains. The former speaker cited his record during his reign over the House when, under President Bill ClintonWilliam (Bill) Jefferson ClintonFamily, friends mourn death of Barbara Bush Dems press for hearings after Libby pardon The Hill's Morning Report: Hannity drawn into Cohen legal fight MORE, the budget was balanced and taxes were cut.

“Part of the difference is I do change things when conditions change. Part of the difference is I struggle for very large changes,” Gingrich said.

Written off by many during the early months of the campaign, Gingrich has emerged to fill the void left by a handful of fellow candidates who surged early but then deflated just as quickly.

Recent polls in Iowa show him with a double-digit lead over former Massachusetts Gov. Mitt Romney (R), the No. 2 finisher in the Hawkeye State. But Romney and others have upped their attacks on Gingrich as the Iowa caucuses draw nearer.