LAS VEGAS, Nevada -- At Mitt Romney’s first rally here earlier this week, there were plenty of hints that the enthusiastic crowd of 1,000 was stacked with Mormons. Kids walked around in BYU sweatshirts, moms chatted about LDS youth groups, and at least one supporter was overheard talking about making phone calls for the candidate as part of "family home evening" -- a weekly family night the church encourages its members to hold.

But while it's no secret that Romney's coreligionists have swelled the ranks at campaign stops from Des Moines to Reno, one question about the Mormon vote has gone largely unanswered this primary season: How, exactly, have they gotten so organized?

"We heard about it from some friends in our [LDS] ward," said one woman standing outside a rally held in a Las Vegas hotel supply warehouse. "We're so glad we could make it." Another Mormon standing nearby chimed in, "Everyone we know is voting for Mitt!"

The secret to the grassroots success lies, in part, in the unique national structure and scrupulous record-keeping of the Utah-headquartered Church of Jesus Christ of Latter-day Saints. While the church itself is politically neutral, it contains the structural groundwork for one of the most organized and effective voting blocs in the country—something Romney is poised to capitalize on.

Here’s how it works

In contrast with most other religions in the country, the Mormon Church is nationally organized in a strict, top-down fashion, like a corporation. Every congregation in the U.S. reports back to church headquarters in Salt Lake. Whenever an individual is baptized -- either as a child or as a convert -- local ministers take down the person’s name, address, phone number, and e-mail address, and feed the information into a national database maintained by officials in Salt Lake (and only accessible to certain church leaders).

From there, the individuals are assigned to geographically-determined congregations -- or “wards” -- of about 200-300, which they attend on Sundays. Their contact information is filtered into a local “ward list,” which is distributed to all local congregants for planning purposes--from coordinating Sunday school, to working out the logistics for church barbeques.

For decades, these ward lists were printed out and distributed after Sunday services, but in recent years the system has migrated online to LDS.org, where Mormons create logins to access the contact information for every fellow believer in the area.

For active Mormons, wards often become the center of their social universe: it’s not uncommon for members to visit their local chapels three or four times a week for various activities and meetings. Additionally, Mormons participate in “home and visiting teaching” programs, which require them to visit certain ward members on a monthly basis. In this context, ward lists become invaluable tools for Mormons’ daily life—inevitably finding their way into Google groups, listservs, and cell phones.

They also frequently become political tools.

Working the wards

The church expressly forbids using these directories for non-religious purposes, but that doesn’t deter many politically active Mormons from working their ward lists to get out the vote. Reports abound of members blasting out congregational e-mails soliciting support for partisan causes and candidates. One Southern California ward received several e-mails urging congregants to vote for an LDS politician running for local office. And in nastier example of the practice, ward lists in Alpine, Utah were used to spread an anonymous smear campaign against a candidate on the eve of a local election.

Several Mormons told BuzzFeed that as the 2012 primaries heated up, they started to see their fellow congregants use ward lists to organize local efforts for Romney.

Here in Nevada, Ryan Erwin, a consultant for the Romney campaign, acknowledged that the candidate has benefitted from grassroots efforts by Latter-day Saints, and said the campaign is proud of their support. But he also thinks the Mormon factor has been overstated.

“Mormons make up seven percent of the population here,” Erwin said. “If you read some of the reports in the media, you’d think it was 90 percent… it’s a little aggravating when you’ve worked for months to build up an organization and then they say, ‘Well, he just won it because he’s a Mormon.’”

That said, exit polls in 2008 showed that about 25 percent of Nevada caucus-goers self-identified as Mormon -- and Romney won that primary handily. This time around, polling indicates that he’s headed for a similarly dominant victory, and if it happens, local Latter-day Saints will no doubt deserve a chunk of the credit.

Much like how Iowa’s Christian home-school vote advanced its own grassroots efforts for Mike Huckabee largely independently of his campaign, there’s no evidence that Team Romney is officially coordinating with Mormon congregations. But anecdotal evidence suggests that a highly motivated base of Mormon supporters has effectively taken advantage of the LDS infrastructure to help Romney.

The Colonial First Ward listserv

One of the most illustrative examples is the Colonial First Ward listserv, which consists of more than 3,500 D.C.-area Mormons, many of them young and single.

E-mails obtained by BuzzFeed show the listserv being used frequently as a recruiting tool for Romney supporters -- gathering signatures to get the candidate on the Delaware ballot, requesting volunteers to aid the campaign’s Illinois operation, and organizing a get-out-the-vote trip to South Carolina on the weekend of the primary.

The fruits of that last effort were obvious on the ground in Columbia, S.C., where dozens of young Mormon students from Virginia and D.C. were found rallying for Romney at various campaign stops.

But not everyone on the listserv has looked kindly upon efforts to transform the network into a booster club for Romney, and a number of members have e-mailed complaints.

Matt Larsen, a member of the listserv, wrote last October: “I know I’m probably going to make enemies here, but I’m getting really tired of the ads for Romney campaign trips coming from this list serve. The disclaimer at the bottom of every list serve email states very clearly: ‘Items that will not be posted/that will be removed include: promoting your business, promoting political ideologies, and inflammatory comments and rhetoric.’”

The protests appear to have been ignored though, with members continuing to send out e-mails as recently as last month that requested volunteer help for Romney.

“The Colonial First Ward listserv seems to be a miraculous pro-Romney organizing tool,” grumbled one D.C.-area Mormon, who is a Democrat. “Whenever you get the contact information for 3,540 young Mormons in one place, I guess it has to be.”