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Gingrich takes control in Iowa

With about four weeks until the first Republican presidential nominating contest, former House Speaker Newt Gingrich has surged to the lead in Iowa and has climbed nearly 20 percentage points in New Hampshire since October, according to new NBC News-Marist polls.

Meanwhile, former Massachusetts Gov. Mitt Romney has seen his support drop in both states.

In Iowa, which holds its caucuses on Jan. 3, Gingrich gets the support of 26 percent of likely caucus-goers (including those leaning towards a candidate) -- a 21-point jump since October.

Read the NBC News-Marist poll Iowa Annotated Questionnaire

He’s followed by Romney at 18 percent (an eight-point decline), Texas Rep. Ron Paul at 17 percent (a five-point increase), Herman Cain at 9 percent (an 11-point drop) and Texas Gov. Rick Perry at 9 percent (a two-point dip). No other Republican presidential candidate gets more than 5 percent support among likely caucus-goers.

With Cain’s decision to suspend his campaign -- which he announced on Saturday -- a reallocation of his supporters’ second-choice picks puts Gingrich ahead of the Iowa horse race with 28 percent; Paul and Romney are tied at 19 percent; and Perry lands at 10 percent. (The NBC-Marist polls were conducted before Cain suspended his campaign.)

Among all Republican respondents in Iowa, the breakdown is Gingrich with 25 percent, Romney at 18 percent and Paul at 16 percent.

Romney still leads in New Hampshire
In New Hampshire, which holds its primary on Jan. 10, Romney continues to lead, getting the support of 39 percent of likely GOP primary voters. But that’s a six-point decline since October.

Romney is followed in the Granite State by Gingrich at 23 percent (a 19-point gain), Paul at 16 percent (a three-point increase), and former Utah Gov. Huntsman at 9 percent (a four-point jump). No other Republican candidate gets more than 3 percent support.

Read the NBC News-Marist poll New Hampshire Annotated Questionnaire

The decision by Cain -- who is at 2 percent support in New Hampshire -- to suspend his campaign doesn’t change the race there all that much: Romney stays at 39 percent, while Gingrich moves one point to 24 percent.

Among all New Hampshire Republicans, the breakdown is Romney with 40 percent, Gingrich with 21 percent, Paul with 16 percent, and Huntsman at 10 percent.

What’s hurting Romney
What appears to be hurting Romney: perceptions of his ideology and his record as Massachusetts governor.

A combined 71 percent of likely Republican caucus-goers in Iowa, as well as a combined 71 percent of likely GOP primary voters in New Hampshire, view Romney as either “moderate” or “liberal.”

Among Iowa Republicans identifying with the Tea Party -- who make up about half of all likely caucus-goers -- Gingrich leads Romney, 32 percent to 11 percent. And among Tea Party Republicans in New Hampshire, Gingrich and Romney are tied at 33 percent each.

What’s more, 63 percent of likely Iowa caucus-goers and 60 percent of likely New Hampshire primary voters say it’s unacceptable if a presidential candidate supports an individual health-care mandate (as Romney helped enact in Massachusetts).

By comparison, 47 percent of likely Iowa caucus-goers and 41 percent of likely New Hampshire primary voters say it’s unacceptable if a candidate favors some sort of limited legalization -- or “amnesty” -- for illegal immigrants living in the United States (as Gingrich has suggested he supports).

Measuring Obama
Turning to the general election in Iowa and New Hampshire, President Barack Obama’s approval rating remains underwater in both states.

Forty-three percent of registered voters in Iowa approve of his job performance, which is up one point from October. In New Hampshire, 40 percent of registered voters approve of his job performance, up two points.

Yet -- with one exception -- he leads all GOP challengers in hypothetical match-ups in the Hawkeye State. He’s ahead of Romney by seven points among registered voters (46 percent to 39 percent), Gingrich by 10 points (47 percent to 37 percent) and Perry by 11 points (48 percent to 37 percent).

The one exception: Paul ties him at 42 percent for each.

In New Hampshire, Romney leads Obama by three points (46 percent to 43 percent), although that’s down from Romney’s nine-point advantage in October.

But Obama leads all other Republicans in the state -- Paul (by two points), Gingrich (by 10) and Perry (by 15).

The Iowa NBC-Marist survey was conducted Nov. 27-29 of 2,896 registered voters (margin of error of plus-minus 1.8 percentage points) 916 Republicans (plus-minus 3.2 percentage points) and 425 likely GOP caucus-goers (plus-minus 4.8 percentage points.

The New Hampshire poll was conducted Nov. 28-30 of 2,263 registered voters (plus-minus 2.1 percentage points), 967 total Republicans (plus-minus 3.2 percentage points) and 696 likely GOP primary voters (plus-minus 3.7 percentage points).

Mark Murray covers politics for NBC News.