Guilford County seemed ripe to reject the constitutional amendment banning same-sex marriage. It’s a heavily Democratic, urban county chock full of colleges and universities with the young voters that amendment opponents focused on getting to the polls.

In the end, Guilford joined 91 other counties that voted to ban same-sex marriage and civil unions. As the amendment swept to passage with 61 percent of the May 8 vote, only eight counties opposed it.

The constitutional ban on same-sex marriage and civil unions becomes official Wednesday after the State Board of Elections certifies the vote.

Commentary and explanations for the outcome started before all the votes were counted May 8 and continue today.

Robert Eldredge, co-founder of the local group We Are, was surprised by the result. We Are started working against the amendment months before the official statewide campaign was organized.

North Carolina became the 31st state to add a marriage amendment to its constitution.

“That was really shocking for us,” Eldredge said. “I had real high hopes.”

Ninety miles away, two graduate students at UNC-Charlotte wanted more details than could be gleaned from an online map showing the expanse of blue counties that supported it and the few islands of red-colored counties that rejected it.

They built interactive maps using State Board of Elections and U.S. Census Bureau information that show gradations of support for the amendment and give demographic information for each county.

Lane Harrison, a graduate student in computer science at UNC-Charlotte, said the interactive maps he and fellow student Drew Skau developed may be a start for people who want to dig deeper.

Their main map on the vote distinguishes the degrees of support for the amendment. Orange County, where voters rejected the amendment 79 percent to 21 percent, stands out in the deepest blue. Counties that voted heavily for the amendment, as Robeson did – voting 86 percent in support – are the deepest yellow.

“I was completely aware that most maps would not tell the full story,” Harrison said.

In the students’ map, Guilford, home to two state universities and where the amendment won by 42 votes, looks more like Watauga, home of Appalachian State University, where it lost by 244.

It remains to be seen whether the results inspire the kinds of dissection, research and analysis that California’s Proposition 8 did after voters there passed a constitutional amendment in 2008 that eliminated the right of same-sex couples to marry.

Harrison and Skau started talking about making the maps the day after the vote and are still refining them.

The maps have limitations. The demographic information comes from the census, and does not have information specific to May 8 voters. It doesn’t account for all universities, just the state schools and the largest private universities.

In the long term, the dissection of precinct-by-precinct information may be more valuable than the broad county statistics.

In Guilford, for example, Eldredge said the lack of an early-voting polling site on UNC-Greensboro’s campus hurt student turnout.

“It makes it very difficult for them,” Eldredge said. “The closest early voting site is about a 1 1/2-mile walk.”

Still, the maps can be a start for those who want a closer look at the results, particularly those in voters’ backyards, Harrison said.

“The visualizations could be a jumping off point for further analysis and answering questions about one’s own county,” he said.

Tami Fitzgerald, chairwoman of the campaign supporting the amendment, said she was not surprised to win Guilford. Grassroots coordinators were at work in every county, she said, and ads supporting the amendment ran statewide.

“Every county in the state was a battleground,” Fitzgerald said. “We wanted to win every precinct, every county.”

Bonner: 919-829-4821