NEW YORK -- There are two prisms through which to view President Obama's LGBT fundraiser on Thursday night. The first is presidential politics and, mainly, Obama's continued evolution on gay rights. New York is poised to pass a law legalizing same-sex marriage, making the president's reluctance to come out in favor of it (despite clear signs of support in the past) the source of obvious tension. The second, more telling prism, is the political potency of the gay rights movement itself.

In less than a decade, the LGBT community's sway over the political narrative in the country has grown as fast -- if not faster -- than its membership. Once shunned by politicians, gay rights leaders and donors are now courted by Democratic candidates (and even some Republicans). Advocacy groups have sprouted both locally and nationally. Coverage of LGBT-related issues has gotten front-page treatment in newspapers and top billing on blogs.

The combined effect has been incredibly beneficial to LGBT causes, casting them up the list of pressing political topics. But it also has produced a tension in its own right among gay rights groups. There is, on the one hand, the veritable old guard, who recalls the days when they were part of the national political sideshow. And then there is a new generation of activists -- not all of them young, per se -- far less willing to see their priorities addressed in incremental fashion.

"Years ago, I would absolutely defend politicians who didn't come out for marriage because I felt it was just falling on your sword," said John Aravosis, the gay rights activist, prominent blogger, and vocal critic of incrementalism. "Now … things have gone into hyperdrive in terms of advancement of the movement."

When Obama takes the stage on Thursday night he will be addressing both groups. But as long as he doesn't make an implicit endorsement of same-sex marriage, he will be welcomed far more warmly by the former than the latter.

"This is the third president in which I've been very focused on LGBT advancement in terms of Washington," said Elizabeth Birch, the former Executive Director of the Human Rights Campaign who will be in attendance on Thursday. "The fact remains this is the very first president who has every broken through that thick congressional wall for our rights."

As Birch sees it, national politics is "like playing chess, underwater in a toxic swamp." To repeal Don't Ask Don't Tell, codify employer protection benefits and hospital visitation rights, and begin down the path of doing away with DOMA is a slate of accomplishments worth praising. Marriage is the prize and purview of the next generation.

"I am so old that one of the biggest advantages of being a lesbian, when I figured it out, is that I didn't have to get married," Birch said. "Now it is sort of the hot thing. That is the absolute job of youth. It is to act as if all things should already exist and that it is possible and obtainable if the will is there."

Generational divides have long been a defining feature of the LGBT community, driving activists and advocacy groups to conduct their politics in demonstrably different ways -- be they chaining oneself to the White House fence or pushing for inclusion in the White House strategy meeting. Richard Socarides, president of Equality Matters, recalled how, not too long ago, gay rights activists were practically "giddy" at the prospect of being invited to a presidential event, let alone hosting a high-profile gala. It was President Bill Clinton who first reached out to the gay political community, getting longtime activist David Mixner to drum up support for his campaign (Mixner would later abandon Clinton over DADT and DOMA).

"It was breathtaking," recalled Socarides, who served in various positions in the Clinton White House, "because it was the first time anybody had ever sought our support. Up until that moment candidates didn't even want to be associated with us. Jimmy Carter famously went to San Francisco and didn't even want to be photographed with Harvey Milk."

Today, feeling comfortable taking a photo doesn't cut it. And Obama won't be absolved merely by attending a gala or hosting a Gay Pride event at the White House (as he is set to do next week). The administration, Socarides notes, has helped produce laudable achievements on LGBT issues. But "if there is a calculation on marriage, it is always that if people don't have any alternative, they can hang out in the middle without consequence," he said. "I would say to them there is a big downside to looking inauthentic, and right now they look inauthentic."

Indeed, despite improved relationships with some of the very same gay rights activists who once protested the president's fundraising events, Thursday's gala still risks being overshadowed by the singular issue of same-sex marriage.

The president is not expected to address the political developments in New York, and if he does it, will likely be through the rather stale construct of respecting the sovereignty of states. It won't necessarily be demoralizing for attendees. But it will prolong the often-intense debates among LGBT activists over how, exactly, they should exert their widening political clout.

"There are two different camps," said Mixner. "One is 'don't pressure him on marriage, we will get it eventually, it is okay, he has done more than any other president, let's not be hard.' Then there is a group that I include myself in, which will support the president's re-election but who will not let up on marriage. We feel this is not a political issue, it is a moral issue where he needs to exert moral leadership."

