Maine has more same-sex couples per capita than all but six states, according to a new analysis of 2010 U.S. Census data.

Additionally, South Portland and Portland have become particular hot spots for gay couples, the statistics show, outpacing Boston, Cambridge and other gay-friendly cities.

Some local historians and gay-rights activists attribute the state’s high concentration of same-sex couples to its gay-friendly laws. Although same-sex couples can’t marry in Maine, they can use the Family Leave and Medical Act and adopt children – one of only about 15 states that implicitly or explicitly grant those privileges, activists said.

The state also has anti-discrimination laws that protect lesbian, gay, bisexual and transgender residents, said Betsy Smith, the executive director of EqualityMaine, a nonprofit organization that fights for gays’ and lesbians’ civil rights.

And residents of southern Maine – and Portland and South Portland, in particular – have embraced or at least tolerated counterculture, which has helped attract gays and lesbians, said Stephen Marks, a professor emeritus of sociology at the University of Maine.

“Word circulates about which communities are tolerant of same-sex couples,” said Marks, who for many years taught a class titled, “The Sociology of Lesbian and Gay Families.”

“Obviously, people are more likely to live where they are welcome.”

Smith described a “snowball” effect. Once a gay-friendly culture was established in Portland, it became a more attractive location for gays and lesbians to live. It’s “the way life should be,” she said, quoting one of the state’s tourism slogans.

“Maine has a lot to offer,” Smith said. “It’s a pretty good business climate. It has excellent schools. It has a great outdoor environment. You can be in a city and enjoy the things a city has to offer, and then go out skiing, or to camp, or go to the beautiful coastline. It’s just a beautiful place to live, and that applies to same-sex couples as well.”

Some of the state’s attraction for gays and lesbians is rooted in its history.

Between the early 1900s and World War I, the state attracted a lot of gay writers and painters from Philadelphia, Chicago and New York to picturesque, yet sparsely inhabited parts of the coast, according to an article titled, “Creating a ‘Gay Mecca’: Lesbians and Gay Men in Late Twentieth-Century Portland,” by University of Southern Maine history professor Howard Solomon.

The rural setting allowed gays to avoid persecution.

Early 20th-century photos of a summer community on Bailey Island in Casco Bay captured same-sex couples and drag shows.

The state’s real attraction for gays and lesbians, however, came after the arrival of John Preston in 1979.

Preston, one of the most successful gay writers of his time, published weekly letters in gay publications across the country depicting and promoting Maine as a potential mecca for gays and lesbians.

The success of his “Letters From Maine,” which earned syndication in Minneapolis, Miami, Boston and many other cities, undoubtedly led to Maine’s reputation as an attractive place for gays to live.

Preston also published 42 books, led the city’s first gay-rights demonstration and organized the city’s first AIDS organization.

“More than anyone else, Preston was responsible for recasting Maine’s reputation as an inhospitable place for gay people into a hospitable, welcoming one,” Howard wrote.

Maine has about 9.7 same-sex couples for every 1,000 households, according to the latest report. The Williams Institue at UCLA Law School – which studies sexual-orientation issues – culled the statistics from the 2010 U.S. Census data. Reserachers identified same-sex couples when one person in a household described his or her relationship with another person in the same household as “husband/wife” or “unmarried partner.”

Vermont, Massachusetts and California led the country, each with 10 same-sex couples per household or higher. After those three, Maine trailed only Oregon, New Mexico and Delaware.

North Dakota (3.96) and South Dakota (4.31) had the fewest number of same-sex couples for every 1,000 households, with Wyoming not far behind.

In terms of cities with more than 100,000 people, Fort Lauderdale (35.80) and San Francisco (33.41) led the way. In cities with fewer than 100,000 people, Provincetown, Mass., had the most same-sex couples per 1,000 households (163.11), but South Portland and Portland still ranked high on the list.

It’s unclear what the impact would be if Maine passed legislation recognizing same-sex marriages. In 2009, 53 percent of voters rejected allowing gay marriage, but it’s likely to be back on the ballot again in 2012.

Only five states have legalized gay marriage since Massachusetts became the first to do so in 2004, and not enough time has elapsed to collect data on how that has affected those states’ gay populations.

But because Maine already has a relatively gay-friendly reputation, and because people tend to move for economic and familial reasons more than anything else, Marks said he doesn’t think passing such legislation would have significant impact on the number of gay couples in Maine.

Jason Singer can be reached at 791-6437 or:

jsinger@pressherald.com