AP Poll: Outside money more potent issue than gender in 2016

Nineteen percent of Americans say they would be more likely to vote for a presidential candidate if the person is a woman, according to a new Associated Press-GfK poll, while 64 percent say a candidate's gender has no bearing on their vote.

In a sign of Sanders' potent message on political money, the poll finds that 46 percent say they're more likely to vote for a candidate who doesn't want outside groups supporting his or her campaign.

Sanders notes his opposition to super PACs at every event and rails against the influence of "millionaires and billionaires" in the political system.

Clinton is more overt about her attempt to break the glass ceiling compared to her 2008 presidential campaign, when she emphasized her experience and toughness.

In the first three contests, Sanders has won an overwhelming support among young voters, including women, while Clinton has generated enthusiasm among older voters, including women from the Baby Boomer generation.

The poll also showed businessman Donald Trump's staying power, as 56 percent of Republicans surveyed said a candidate's decision to refuse the support of outside groups would make them more likely to vote for that candidate.