Bruce N. Gyory is a political consultant with Corning Place Consulting in Albany and an adjunct professor of political science at the University at Albany.

In 2009, when the New York State Senate first voted on same-sex marriage, Long Island's senators correctly saw that public opinion on the issue was divided. When the prospects for passage receded, opposition became the more prudent choice. None of the seven Republicans voted "aye."

Today, as Long Island's nine Republican senators survey the politics of gay marriage, they see a much different picture.

The shift in public opinion toward support of same-sex marriage has been accelerating at a phenomenal pace. Where it once took political courage for a suburban senator to vote in favor of the legislation, it now may be perilous to oppose it.

While a Pew Research survey last month found that, nationwide, support for gay marriage is at 45 percent, and opposition is at 46 percent -- a dead heat -- as recently as 2008, only 39 percent supported gay marriage, while 51 percent were opposed.

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By August of last year, a CNN poll became the first national survey to find a narrow majority in favor of gay marriage. The CNN data also revealed startling levels of support in certain states, including Massachusetts, where gay marriage is legal (62 percent), and New York (58 percent). Critical mass in any given state comes when support crosses 60 percent and reaches 2 to 1 in favor.

Past polling has shown that age is the key variable in determining views on gay marriage. Voters younger than 40, especially those with college degrees, strongly support same-sex marriage, while those over 60 oppose it. But if age were the only factor, support would increase by just 1 percent to 2 percent a year, not the 4 percent annual increase in support and decrease in opposition now being seen.

And support is coming from somewhat surprising places. A national Washington Post-ABC poll last month found support at 63 percent of white Catholics.

Increased support for gay marriage tracked the movement in public opinion toward repealing "don't ask, don't tell": Support first rises among Democrats and liberals, but then independents and moderates break away from broad Republican and deep conservative opposition.

Earlier this month, a Siena Research Institute poll repeated last year's CNN results, finding that 58 percent of New Yorkers support gay marriage. But the real story lies in the level of support from key New York subgroups.

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In the suburbs, 64 percent support the legislation. Women favor gay marriage by 60 percent; independents, 61 percent; Catholics, 59 percent; 35- to 54-year-olds, 63 percent. The trend line in support for gay marriage in New York is clearly accelerating. Support in New York will cross that critical mass of 2-to-1 in the suburbs by Labor Day 2012.

While the Siena poll doesn't separate Long Island from the rest of its suburban data, Nassau and Suffolk are home to 71 percent of registered voters in the four counties traditionally defined as New York's suburbs. So these results provide a clear picture of how registered voters on Long Island view same-sex marriage.

One can feel a certain empathy for New York's suburban Republican legislators. On gay marriage, their base -- buttressed by the Conservative Party -- is pulling them hard toward a "no" vote. But the rising ranks of independents will increasingly neither understand nor support anything other than a "yes" on gay marriage.

So wise Republicans in New York are probably hoping that the gay marriage bill passes this year, well before next year's elections. As Massachusetts, Vermont, Connecticut, New Hampshire, Washington, D.C., and even Iowa have shown, after gay marriage is enacted and if repeal is not possible, political rancor about it disappears. Voters move on to other issues, choosing to live and let live on same-sex marriage.

Opposition to gay marriage, which began as a wedge issue used by the Bush campaign in 2004 to increase conservative turnout, has become an inverse wedge, threatening suburban Republicans in states like New York, where the votes of younger, highly educated Catholics and their parents hold the decisive balance of electoral power.