Houston » When an openly gay woman won the mayor's race here earlier this month, it was the latest in a string of victories by gay candidates across the country, a trend that seems to contradict the bans on same-sex marriage that have been passed in most states in recent years.

Take Texas, by many measures one of the most conservative states in the nation. In 2005, Texas became the 19th state to enact constitutional amendments banning same-sex marriage; the voters passed the referendum by a ratio of 3 to 1.

Yet in the last decade, an openly gay woman has twice won election as the sheriff in Dallas County and another openly gay woman was elected district attorney in Travis County, which includes the city of Austin. Gay candidates have also won city council seats in Austin, Fort Worth and Houston.

Then, this month, Annise Parker, the city controller who is a lesbian, swept to a solid victory in the mayoral race in Houston, the nation's fourth largest city.

And while Parker's victory in Houston, a city of 2.2 million people, marked the biggest victory for gay-rights advocates this year, gay candidates made strides in other places in the last election cycle.

Charles Pugh, an openly gay former broadcaster, swept to victory as City Council president in Detroit in his first bid for public office. Akron, Ohio, elected its first openly gay council member, Sandra Kurt, an industrial engineer at Goodyear Tires.

Some political scientists say the rise in openly gay candidates' winning public office is a better barometer of societal attitudes than are the high-profile fights over same-sex marriage.

"Gay marriage ballot measures are not the best measure," said Patrick J. Egan, a political scientist at New York University who studies issues surrounding gay politicians. "They happen to be about the one issue the public is most uncomfortable with. In a sense they don't give us a real good picture of the opinion trend over the last 30 years."

For instance, the National Opinion Research Center at the University of Chicago has been polling people since 1973 about whether homosexual behavior is morally wrong. In 1973, 73 percent of the people polled described it as always wrong and only 11 percent as "not wrong." By 2006, those saying homosexuality was "always wrong" had dropped to 56 percent, and 32 percent said it was not wrong.

One reason for the shift in attitudes, some political scientists contend, is a rising number of homosexual people acknowledging their sexual preference openly in various walks of life, from workers on factory floors to Hollywood stars.