Poll: Donald Trump nearly doubles lead in New Hampshire

By Jennifer Agiesta, CNN Polling Director

Updated 5:46 PM ET, Tue December 8, 2015

Washington (CNN)Donald Trump has a growing lead among likely primary voters in New Hampshire, and both he and Marco Rubio have gained ground in the state since September, according to a new CNN/WMUR poll conducted by the University of New Hampshire Survey Center.

Overall, 32% say they support Trump (up 6 points since September), with Rubio a distant second place with 14% (up 5 points). That 18-point lead is almost double the 10-point lead Trump held in September over businesswoman Carly Fiorina.

New Jersey Gov. Chris Christie holds third place in the new poll with 9%, followed closely by former Florida Gov. Jeb Bush (8%), Ohio Gov. John Kasich (7%), Texas Sen. Ted Cruz (6%), and both businesswoman Carly Fiorina and former neurosurgeon Ben Carson at 5%. Fiorina has dropped 11 points since the September poll.

The New Hampshire poll comes on the heels of CNN/ORC surveys in Iowa and nationally both showing Trump with growing leads over the rest of the GOP field. The poll was conducted almost entirely before Trump issued a policy statement calling for a temporary ban on allowing Muslims who are not U.S. citizens to enter the country.

Nearly 6-in-10 likely New Hampshire Republican primary voters now say they think Trump is most likely to win the GOP primary in the state, up 19 points from 40% saying so in September. No one else is in double-digits on this question. Looking ahead to the general, 34% think Trump has the best shot to win the White House, 17% say Rubio does, 7% say Christie and 6% Bush.

The landscape of the campaign has changed since the September poll, with foreign policy and national security taking a more prominent role. Half (50%) now call that a top issue, up from 21% in September, while the previous top issue -- jobs and the economy -- is now the most important issue for 18% of likely Republican primary voters.

Trump is seen as best able to handle ISIS, with 33% saying he is the candidate best able to handle the militant group. Republican voters appear divided on who else would do a good job on ISIS, with five other candidates all bunched together around second place: 11% name Bush, 9% Christie, and 7% each Cruz, South Carolina Sen. Lindsey Graham and Rubio.

On taxes and spending, Trump is the clear leader, with 42% calling him best able to manage government spending and 36% best able to handle taxation -- his next closest competitor in both cases is Bush at 10%. Trump also holds a wide lead as most trusted to handle immigration, 45% to 14% for Rubio and 11% for Bush.

There have also been some shifts in the poll in favorability ratings since September. Rubio is now viewed most favorably, with 61% holding a positive view of him and 23% unfavorable. That's not a significant change since his September rating, but others who were viewed more positively have lost significant ground. Favorable impressions of Fiorina have fallen from 62% in September to 49% now, and Carson has dropped from 60% in September to 47% now. Kasich's favorability rating drops from 45% to 36%, and there's also been an uptick in negative views of Bush, from 36% in September to 45% now.

The CNN/WMUR poll was conducted by the University of New Hampshire Survey Center by telephone from November 30-December 7. The poll includes interviews with a random sample of 954 adult residents of New Hampshire, including 402 who say they plan to vote in the Republican presidential primary. For results among the sample of GOP primary voters, the margin of sampling error is plus or minus 4.9 percentage points.