Hillary Clinton's 11-hour testimony on the 2012 Benghazi attacks may have helped her overall in the polls, but when it comes to millennials, particularly younger women, Clinton continues to fall behind Vermont Sen. Bernie Sanders.

An astounding 71 percent of likely Democratic primary voters in South Carolina said that they are leaning towards Clinton, while 15 percent said the same for Sanders, according to a new poll released by Winthrop University Wednesday.

As for Clinton's performance before the House Select Committee on Benghazi last month, a Wall Street Journal/NBC News poll released Tuesday found that 72 percent of likely Democratic primary voters now feel satisfied with the answers the former secretary of state provided about the attacks on the U.S. diplomatic compound in Libya. That's compared to the 58 percent who were satisfied before Clinton spent the entire day testifying. Republicans remained dissatisfied, with only 7 percent saying they are content with Clinton's answers.

And while Clinton generally does well with women voters, younger women and younger voters overall seem to prefer Sanders and his calls for political revolution.

An NBC News/SurveyMonkey poll released Friday found Sanders, an independent senator running on the Democratic ticket, garnering 48 percent support from young voters between the ages of 18 and 29. That's compared to Clinton's 33 percent.

The poll didn't break down support by gender, but Democratic strategists have pointed out that support from young women is a huge vulnerability for Clinton, according to The Hill.

Millennial women are more "enamored" with Sanders and are slightly put off by Clinton's personality, says Peter Hart, a top Democratic pollster.

Clinton's policies and experience aren't necessarily the problem, but "when it comes to the more personal side, whether she is easy-going, likeable, relating well, she does less well," Hart told The Hill.

Another Democratic strategist said Clinton seems "too old, too moderate and too caught up in another time."

Katherine Jellison, a professor of women's history at Ohio University, thinks it's more of a generational issue.

"She's your mom's candidate," Jellison said. "She and the Clinton machine seem like old news to a lot of millennial. And if you think about where youthful activism has been - other than LGBT issues - it really hasn't been with gender issues but class issues, like the Occupy movement."