About 31 percent of female respondents — or 1,558 women Marines — say they would be interested in a lateral move to a combat position as their primary job, and 34 percent — or 1,636 — said they would volunteer for a ground combat unit assignment.
Elaine Donnelly of the conservative Center for Military Readiness and a vocal critic of the change said the survey asked the wrong questions and should have been asking if troops favor it and whether it will make a more effective force.
The questionnaire also relied on the "mistaken belief" that training standards will remain the same, which Donnelly said is not realistic given the differing physical abilities between the genders.
She said the Pentagon is bent on imposing gender-based quotas that will drive down standards. Defense leaders say standards will not be lowered.
"The results that are being put out there are designed to manage public perception," she said. "There is a lot about this that still needs to be discussed and it's really not fair to the women who serve out there."
The infantry side is skeptical about how women will perform in their units, and some positions may end up closed again if too few females meet the physically demanding standards of combat, said Gen. James Amos, head of the Marine Corps, who spoke to reporters Thursday at a defense conference in San Diego.
"I think from the infantry side of the house, you know they're more skeptical," Amos said. "It's been an all-male organization throughout the history of the U.S. Marine Corps so I don't think that should be any surprise."
Most Marines support the policy change, Amos said.
It will be up to the military service chiefs to recommend and defend whether women should be excluded from any of those more demanding and deadly positions, such as Navy commandos or the Army's Delta Force.
Over the past decade, many male service members already have been fighting alongside women in Iraq and Afghanistan. Women who serve in supply units, as clerks and with military police have ended up on the unmarked front lines of modern warfare.
More than 150 women have been killed in wars in Iraq and Afghanistan while serving in support roles.
About 7 percent of Marines are female compared to about 14 percent overall for the armed forces.
Both sexes surveyed said getting women closer to the action will improve their career opportunities.