As New York gears up for its second weekend of same-sex nuptials, a Washington Post-ABC News poll finds Americans split 50 to 46 percent over whether the state’s law legalizing such unions is a positive or negative outcome. Reactions to the new legislation — like support for legalizing gay marriage in general — range tremendously across generational, political and religious lines.

Americans have grown increasingly accepting of same-sex marriage over the past decade, according to surveys by The Post and ABC, Gallup, the Pew Research Center and others. The public opposed legalizing gay and lesbian unions by a 58 to 36 percent margin in 2006, but the new Post-ABC poll finds a slight majority — 51 percent — saying such marriages should be legal.

The age gap is one of the brightest dividing lines on gay marriage and on the New York law in particular. Adults under age 30 welcome the new law by a roughly 2 to 1 margin. But six in 10 seniors give it a negative assessment, compared with one in three who take a positive view.

Partisan fissures pose challenge for 2012

Democrats and Republicans react in opposite ways to the new law, each facing stark internal divisions that may present challenges to building a winning coalition in 2012.

Among Democrats, the divide is between the liberal base and those with conservative or moderate stripes. Liberal Democrats view the law positively by an overwhelming 74 to 25 percent margin. A smaller 54 percent majority of moderate and conservative Democrats say the same.

Among African Americans, another loyal segment of the Democratic party coalition, more than six in 10 say the law is a negative development, while roughly one in three see it positively.

Republicans broadly reject the law by a 2 to 1 margin, but alignment with the tea party movement complicates political calculations concerning the issue. More than seven in 10 Republicans who support the tea party movement view the New York law as a negative development. But that slides to just 45 percent of non-tea party Republicans who reject the law, while half react positively.

Protestants and Catholics internally divided over law

Beyond the political divisions over the New York law, religious differences cut just as sharply among white Protestants. More than seven in 10 white evangelical Protestants call the new law a negative development, but white non-evangelical Protestants take the opposite view by a 63 to 34 percent margin.

Catholics overall are more closely aligned with mainline Protestants in their views of the gay marriage law — 58 percent see it as a positive development. Religious observance plays a role, too. Catholics who attend Mass weekly split evenly, 48 to 48 percent, on the law, but less observant Catholics welcome it by a more than a 2 to 1 margin, 66 to 31 percent.

Church attendance is a deep fault line in reactions to the gay marriage law among all Americans, regardless of their particular affiliation. Fully two-thirds of adults who attend worship services at least once a week say the law is a negative development, while 73 percent of those who never attend church react positively to the legislation. Americans who attend church less regularly offer a tepid support; 54 percent react positively, 42 percent negatively.