By Susan Guyett
INDIANAPOLIS (Reuters) - Support for Senate candidate Richard Mourdock has fallen since his recent controversial comments about rape, giving Democrats an unexpected opportunity to pickup a seat on November 6, a poll released on Friday showed.
Eighty-seven percent of respondents in an independent Howey-DePauw Indiana Battleground Poll said they were aware of the remark by the Indiana Republican in a campaign debate on October 23 that pregnancy resulting from rape was "something God intended to happen."
Forty percent of those polled said they were less likely to vote for Mourdock because of the comment, 6 percent were more likely and 54 percent said it made no difference.
The poll showed Democratic Congressman Joe Donnelly with a 47 percent to 36 percent lead over Mourdock among likely voters. Libertarian Andrew Horning was preferred by 6 percent and 11 percent were undecided.
A survey by the same independent polling group in late September had Donnelly leading Mourdock by two points - 40 to 38 percent - which is a statistical dead heat because the margin of error was 3.5 percent.
If Donnelly wins the Indiana Senate seat it would be a major blow to already dimming Republican hopes of taking a majority in the U.S. Senate. They need a net gain of four seats if President Barack Obama is reelected or three seats if Romney wins. Until the Mourdock incident, Indiana was considered a likely Republican win.
Mourdock was the second Republican U.S. Senate candidate to step into a controversy over rape. Missouri candidate Todd Akin said in August that women have natural defenses against pregnancy in cases of "legitimate rape."
Mourdock said that in making his comment about rape, he was trying to express his view that abortion should be banned except in cases where the life of the mother was at risk. Rape should not be an exception to an abortion ban, Mourdock said.
He later apologized if anyone misunderstood his remark and said he abhorred rape and violence against women.
Akin was shunned by many Republicans after his comments, and presidential candidate Mitt Romney asked him to quit the Senate campaign, which Akin refused to do. He has trailed incumbent Missouri Democratic Senator Claire McCaskill in most polls since then.
Most Republicans have continued to support Mourdock.
However, Mourdock was already facing some grumbling within the Indiana Republican party after he ousted longtime Senator Richard Lugar in the Senate primary. The final Howey-Depauw poll before that primary correctly predicted Mourdock would defeat the respected senator and was close to the margin of victory.
Mourdock's campaign criticized the new poll, conducted jointly by Democratic and Republican pollsters, saying its own internal survey showed Mourdock ahead by 46 to 44 percent.
"Fred Yang, the famous Democrat pollster, must have surveyed Illinois. Our polls show us ahead. Our poll follows trends in both the Presidential and Gubernatorial races in Indiana," Mourdock spokeswoman Ashley Varner said.
Donnelly spokeswoman Elizabeth Shappell said: "It is clear voters are rejecting Richard Mourdock's 'my way or the highway' approach to politics."
The Howey-DePauw poll surveyed 800 likely voters from October 28 to 30 and has a margin of error of plus or minus 3.5 percent. The poll reached people with cell phones and landlines. Republican pollster Christine Matthews worked with Democrat Yang on the Howey-DePauw poll.
(Reporting by Susan Guyett; Writing by Greg McCune; Editing by David Brunnstrom)