While Mitt Romney has remained a constant in polling for the Republican presidential nomination at around 25-28%, inconstancy has been the constant among his opponents.  Michele Bachmann became the first to ride a wave to Romney’s relative polling position, only to fade when Rick Perry entered the race.  Now Perry has faded after a series of awful debate performances and Herman Cain has taken his place for the last six weeks.  If Cain can’t maintain his momentum, who will be the next Not-Romney?  Byron York reports from Iowa that it may well be Newt Gingrich:

For days, there’s been talk of a Newt Gingrich boomlet in the Republican presidential race here in Iowa.  After Friday night’s Reagan Dinner at Hy-Vee Hall in downtown Des Moines, that Gingrich boomlet talk might turn into talk of a Gingrich boom.

Five candidates — Gingrich, Rick Perry, Michele Bachmann, Rick Santorum, and Ron Paul — addressed a crowd of about 1,000 GOP faithful at the state Republican party’s biggest fundraiser of the year.  In brief interviews after the dinner — the only question was which speaker did the best job — audience members were unanimous: Gingrich, Gingrich, Gingrich.

“It was Newt,” said Chad Kleppe of Waukee, Iowa.  “I think he’s the smartest one in the field.”

“Gingrich knocked it out of the park,” said Earlene Nordstrom of Fort Dodge, Iowa.

Byron talked to twelve people at the event, and all twelve scored it a knockout for Gingrich.  Neither Romney or Cain made an appearance at the Reagan Dinner.  Romney sent his son, who confessed that he had no idea where his father chose to be rather than the Iowa GOP’s big fundraiser.  York also wondered why Cain, who said this week that he must win Iowa and is conducting a money bomb specifically for that purpose this week, chose to stay in Washington DC rather than try to keep momentum with an appearance.   Both are attending AFP’s Defending the American Dream conference, and Cain has been a regular on AFP’s circuit, and presumably committed to that event long in advance of his sudden rise in the presidential polls.

Why is Newt poised to catch fire?  York credits Newt with a counterintuitive strategy, at least for the former Speaker and his public reputation: he is on a charm offensive.  No, really:

Gingrich won the night in large part by doing one simple thing: He lavished praise on his fellow candidates.  Perry has been “my mentor on the 10th Amendment,” Gingrich said.  Bachmann deserves credit for efforts to stop the Dodd-Frank financial regulation bill.  Rick Santorum has worked to “rouse America to understand the challenge of radical Islam.” Ron Paul has been “consistently correct” about a sound dollar.  Gingrich did not offer praise for the two frontrunners, Herman Cain and Mitt Romney, who skipped tonight’s dinner.  But had they attended, Gingrich said, “I would have said nice things about them, too.”

“I am here with very fine competitors, but no opponents,” Gingrich concluded.  “We only have one opponent, and that’s Barrack [sic] Obama.”

Gingrich has figured out that voters in this primary want to be inspired, rather than choosing which candidate to despise least.  Herman Cain has campaigned the same way, and his optimism and vision has been a key to his ascent to the top tier.  If that seems odd considering Gingrich’s well-earned reputation as an infighter, it’s another indication that Gingrich is a master at politics and campaigning.  He has another advantage that some of his opponents — excuse me, competitors — do not in this regard.  Unlike Tim Pawlenty, Cain, Romney, and everyone else currently or formerly in this race, Gingrich has earned his reputation for hard-nosed battles inside the Beltway.  He can afford to be gracious now, but no one thinks for a moment that Gingrich would insist on a rainbows-and-flowers campaign in a general election.

Gingrich’s polling has begun moving upward in the last couple of weeks.  Who would have guessed in May that Gingrich would have the second-highest positive intensity score in the field in November, tied with Romney behind Cain?  Plus, even though Cain was the immediate beneficiary of Perry’s debate performances, the lesson may well redound to Gingrich’s benefit in the longer run:

“He is so good,” said Becky Ervin of Urbandale.  “I want to see a debate between him and Obama.”

We’ll see more of that tonight in Gingrich’s Lincoln-Douglas style debate in Texas with Cain.  If Republicans want a proven substantive fighter who can out-debate Barack Obama, they may come to Newt Gingrich — even if it’s just by default.

Update: The Right Scoop gives us the video of the speech itself, and it’s just as York described:

I was trying to come up with a word to describe Gingrich’s approach in this primary, and I think the right word is “statesmanlike.” That doesn’t mean he’s the best person for the job, but it’s hard not to take him seriously for the job, either.