By Tim Reid and Chris Kahn
(Reuters) - Donald Trump has dramatically escalated his attacks on his nearest rival for the Republican presidential nomination, Ben Carson. A new Reuters/Ipsos poll may explain why: the billionaire real estate magnate is bleeding support among avid church-goers and women to the retired neurosurgeon.
While the unconstrained Trump has a comfortable double-digit lead over the soft-spoken Carson, the data points to a possible emerging threat to Trump's hopes of capturing the party's nomination for the November 2016 election.
The poll of likely Republican primary voters also shows that Carson is drawing strong support from the rural Midwest, including Iowa, which holds the first Republican nominating contest on Feb. 1. Trump, in contrast, is drawing strong support in the northeast and southeast.
That geographical divide is significant, analysts said, because Carson's dominance in more socially conservative states like Kansas, Iowa and Nebraska reflects how his story of personal redemption is resonating strongly with evangelical voters. They traditionally play an outsize role not just in the first nominating contest in Iowa on Feb. 1, but in Nevada and South Carolina, which also hold nominating votes in February.
"If Carson keeps his nose clean he could win those states and could catch lightning in a bottle," said Ford O'Connell, a Republican strategist not affiliated with either campaign.
Trump, who has topped national polls of likely Republican primary voters for months, has until now enjoyed strong support among the key constituency of low-income, blue-collar, church-going voters, who have been attracted by his image as a straight-talking political outsider.
But Carson's similar appeal as an outsider taking on the Republican establishment has undercut Trump's support in recent weeks, and Carson has surged to the top of a few recent national polls.
Carson's growing support with women and blue collar voters may explain Trump's recent attacks on his rival, said O'Connell. Trump has highlighted media reports questioning elements of Carson's personal story, and on Thursday he called Carson "pathological" and likened him to a child molester.
"Trump is desperate to consolidate the 'outsider' vote. The blue collar vote is very, very key to Trump's success in that. He has tried everything to shake Carson off and it hasn't worked, so he has decided to go nuclear," said O'Connell, an advisor to Republican Senator John McCain's 2008 presidential campaign.
To be sure, a separate rolling five-day Reuters/Ipsos poll shows Trump surging to 42 percent of likely Republican primary voters, up from 25 percent, since Nov. 6 while Carson was flat at 23 percent.
The Trump campaign did not respond to requests for comment on the polling data.
Barry Bennett, Carson’s campaign manager, said of Trump's heightened criticism of Carson: “It’s hard to explain his remarks but clearly he’s feeling some pressure and overreacting.”
Bridget Miller, 43, from Stilwell, Kansas, said she had initially considered voting for Trump, but had switched to Carson. "Carson is pro-life; he's pro-gun; he's saved baby's lives. He speaks to a lot of our values here," she said.
Other likely Republican primary voters say they initially supported Trump but his latest criticism of Carson and his "child molester" comments only confirmed their belief that he is unsuited to the presidency.
Janis Anderson, 54, from Fargo, North Dakota, said she had considered Donald Trump, but his latest comments about Carson were “ridiculous.”
Trump still either leads or shares the lead among most geographical and demographic groups, including wealthy and middle-income voters, people with and without college degrees, the southeast, northeast, the Upper Midwest and the American West.
But the story is different among lower-paid workers. In September, Carson had just over 14 percent of support among voters in households with an annual income of $50,000 or less, according to the broader Reuters/Ipsos data. By the end of October, that had jumped to over 23 percent support. Trump's support in the same group was flat at around 33 percent.
Among likely female Republican primary voters, Carson has seen his support jump since September from about 19 to 27 percent - the highest of any Republican candidate - while Trump's has slipped from 30 percent to 25.
Carson's support among regular churchgoers has also risen sharply, according to the Reuters/Ipsos survey, jumping 10 points between September and November to 32 percent, the highest of any Republican candidate. Trump's support with religious voters has slipped from 26 percent to 22 percent.
"As the campaign has evolved over time, Trump has begun to wear a little bit thin, especially voters who want a softer, more gentlemanly approach to politics," said David Gergen, an adviser to four former U.S. presidents from both parties. "Carson is wearing better with women than Trump."
The surveys of likely Republican voters was taken from Sept. 1 until Oct. 31. The Reuters/Ipsos poll has a credibility interval, a measure of accuracy, of 3 to 8 percent.
(Editing by Ross Colvin)