The latest poll from the Pew Research Center found that a majority of Americans (66 percent) support combat roles for women in the U.S. military. These numbers are unchanged from a survey two years ago.

"Majorities of nearly all demographic groups offer support for allowing women to serve in ground units that engage in close combat," said the Pew Research Center in a statement. These groups include men (65 percent), women (66 percent), Republicans (55 percent), Democrats (76 percent) and veterans (63 percent)."

The smallest majority of support was found among those 65 and older: 52 percent of seniors supported the lifting of the ban, while 36 percent were opposed.

Those who view the introduction of women into combat roles as a major change were less likely to support the policy than those who see it as a minor change.

In terms of military effectiveness, half of those polled said women in combat roles will not make much difference. According to the study, "Of those who do think there will be an impact, more say women in combat roles will make military effectiveness better (29 percent) than worse (15 percent)."

Fifty-eight percent of those polled said allowing women to serve in combat roles will lead to better opportunities for women in the military.

The ban has been in effect since 1994, restricting women from artillery, armor, infantry and other combat roles. However, the nature of combat in Iraq and Afghanistan has not had clear-cut front lines, meaning many military women found themselves in combat regardless.

Secretary of Defense Leon Panetta announced the lifting of the ban of women in combat roles last week."We are moving forward with a plan to eliminate all unnecessary gender-based barriers to service," said Panetta.

Chairman of the Joint Chiefs of Staff Martin Dempsey, who supported the lifting of the ban, also suggested that eliminating the ban could reduce sexual harassment and assault in the armed forces.