A major difference: Nixon turned 55 during the 1968 campaign. In 2016, Gingrich would turn 73.
Tom Perdue, a Republican strategist in Georgia, has long been skeptical of Gingrich's candidacy and believes Gingrich is effectively finished in politics.
"I sure don't see how he could be a contender for anything in the future," Perdue said.
Dan Schnur, the communications director for Republican John McCain's 2000 presidential campaign, said Gingrich has improved his popularity ratings compared with when he was forced out as House speaker. Gingrich should have left the race a month ago, Schnur said, when he could have exited on a better note.
"A string of fourth-place finishes tends to take the shine off," said Schnur. Still, he cautioned against writing off Gingrich from the political scene.
"Each time," Schnur said, "he's managed to climb back."
Associated Press reporter Mitch Weiss in Kings Mountain, N.C., contributed to this report.
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