The attacks against Gingrich were very effective, and it didn't take them very long to have an impact. Let's have a look at the most recent polls and see how Gingrich's lead today compares to what he had less than two weeks ago (with G +01 representing a one-point lead, etc.):
National Primary Polls
G +04 12/22 Gallup -- Gingrich 26, Romney 22, Paul 13, Perry 8
G +00 12/18 CNN -- Romney 28, Gingrich 28, Paul 14, Bachmann 8
G +13 12/18 PPP (D) -- Gingrich 35, Romney 22, Paul 11, Bachmann 7
G +00 12/18 ABC/WashPo -- Romney 30, Gingrich 30, Paul 15, Bachmann 7
G +00 12/18 CBS News -- Romney 20, Gingrich 20, Paul 10, Bachmann 6
Iowa Caucus
G -03 12/20 WeAskAmerica -- Paul 19, Romney 18, Gingrich 16, Bachmann 15
G -02 12/19 ARG -- Paul 21, Romney 20, Gingrich 19, Perry 9
G -08 12/19 Rasmussen -- Romney 25, Paul 20, Gingrich 17, Santorum 10
G -03 12/18 ISU/Gazette -- Paul 28, Gingrich 25, Romney 18, Perry 11
G -09 12/18 PPP (D) -- Paul 23, Romney 20, Gingrich 14, Perry 10
G -09 12/18 Insider Adv -- Paul 24, Romney 18, Perry 16, Gingrich 13
South Carolina
G +17 12/19 Clemson -- Gingrich 38, Romney 21, Paul 10, Bachmann 5
G +12 12/18 Insider Adv -- Gingrich 31, Romney 19, Bachmann 8, Paul 7
The polls reveal a dramatic shift. Even in the national polls, which shouldn't be moved too much by attack ads in Iowa, have Gingrich down. He isn't behind, but he only has a lead in 2 of 5 polls. Putting aside the PPP outlier, Gingrich has only the slightest edge, rather than a 10-15 point lead. There are only two South Carolina polls, and while Gingrich is strong there, he is down a bit from his 20-point lead.
The biggest difference, of course, is in Iowa. Gingrich had enjoyed a 10-15 point lead in Iowa. Now, in the six most recent polls, he is leading in none of them. He's in third place or worse in 5 of 6. In half of them, he's down by more than 5 points. Worst of all, Romney is beating him in 5 of 6.
It's not all due to attack ads. As Elephant Watcher correctly predicted back in October, Gingrich became the next flavor of the month after Herman Cain fell, but was doomed once the Tea Party discovered he wasn't as conservative as they assumed. In addition, Romney has enjoyed an avalanche of endorsements from Republican officeholders, while virtually everyone who ever worked for Gingrich has been against Gingrich.
Given the up-and-down pattern of the primary season, it would be tempting to write off Gingrich now that he's past his peak. But Gingrich, unlike previous flavors of the month, has intelligence and rhetorical skill. He remains strong in South Carolina. Even supposing Romney wins in both Iowa and New Hampshire, Gingrich could pull out a win in South Carolina and play the role of the Anti-Romney for awhile. The odds would be against his winning the nomination, however.
