North Carolina will vote on a proposed marriage ban May 8, when they go to the polls for the Republican and Democratic presidential primaries. And a recent survey indicates that most are likely to approve a constitutional ban on same-sex marriage. But that survey also shows that two-thirds of those people don’t really understand what they’re voting for.

The measure, which some refer to as Amendment One, states that it provides “that marriage between one man and one woman is the only domestic legal union that shall be valid or recognized in this State.” That is interpreted by many as including a ban on civil unions and domestic partnerships.

The poll of more than eleven-hundred people, conducted by Public Policy Polling between March 23rd and 25th, shows 58 percent of likely primary voters will vote for the constitutional ban and 38 percent will vote against it.

Public Policy found that 28 percent of voters think the ballot measure bans only same-sex marriage. And when they were told it also bans civil unions and domestic partnerships, the vote flipped —42 percent opposed and 41 percent favored.

The ballot measure originated in the state’s Republican-dominated legislature which scheduled it for the May primary –a primary that will likely draw many more Republicans than Democrats. Public Policy found Republicans overwhelmingly favor of the measure, while Democrats were split.