For Democrats, one of the shining moments of this year’s legislative session was the passage of a law approving same-sex marriage. For some Republicans, the same moment was seen as one of the Legislature’s deepest failures.

The approval immediately triggered an initiative to try and force a public vote on the measure this fall. So far, the opposing group has collected 70,000 signatures, about half of what they need, and it seems likely to make the ballot.

Why do legislators care one way or another who marries who, and what does it actually have to do with governing? Taxes, education, public safety, land use, roads, mass transit — sure. But marriage?

The answer, as you might expect, has far more to do with politics and elections than it does the art of managing our state government.

While some legislators from each perspective care deeply about whether gays should or should not have the legal right to marry, more care because the people who elect them care.

Democrats tend to view same-sex marriage as an equality issue and a personal matter between two people. They ask, why should the government stand in the way of allowing two people to marry if they want? We don’t tell heterosexual people who they can marry? Although some parents like that concept.

Many Republicans view the matter more in terms of religion and moral values, and believe that marriage should be only between a man and a woman.

This year, the Republicans have been the party with the higher energy level, and their conservative wing has been pushing their candidates farther to the right on many “values” issues including same-sex marriage. They have somewhat reluctantly embraced Mitt Romney as their presidential standard bearer, but many fear he isn’t conservative enough.

As a political matter, Romney would much rather talk about the economy because that is the issue he feels President Obama is most vulnerable on. Some politically savvy Republicans fear that highlighting same-sex marriage, along with abortion and women’s issues, may actually help galvanize Democrats.

They may be right. Democrats have not had the same fire as they did in 2008. Some of their constituent groups have not been as active, particularly young people. While they might have liked the passage of the gay marriage act to just become law and be done with it, they knew that was not going to happen. They now actually see the debate as having the potential to bring back the passion and energy to the election cycle that has been lacking.

While placing the issue on the ballot may bring out more conservative Republicans, they were probably going to vote anyway, as the Republican “get out the vote” effort will be high.

It is the Democratic voter turnout that has been questioned. Gays tend to be liberal to moderate politically, and generally support Democrats, as do many minority groups such as blacks and Latinos.

Republicans recognize that many blacks are conservative on the same-sex marriage issue and most Latinos are Catholic. The Catholic church is actively opposed to gay marriage.

As a strategic matter, Republicans are hoping to wedge those two groups into their camp, while not alienating moderates from their own party or independent voters they are trying to win in November.

How that strategy plays out could be significant. There are many moderates in the Republican party who support same-sex marriage. Four Republican Senators voted for the same-sex marriage bill in our state Legislature, and two gay Log Cabin Republicans are running for Congress — one in Arizona and one in Massachusetts.

After President Obama went public with his endorsement of same-sex marriage, Romney did not come out guns blazing to oppose him. Neither did House Speaker John Boehner. And locally, Republican candidate for governor Rob McKenna’s opposition to same-sex marriage has been muted for months.

Democrats will continue to try and pressure McKenna to make stronger comments, as will the conservatives in his own party. If he does, watch how that affects polling among independents. It may not be good for McKenna.

Republican candidates use the issue to fire up the religious and conservative party faithful, but to the general public, they are much more careful because the public mood has been slowly shifting for several years.

A Washington Post-ABC poll in March found that 52 percent said gay marriage should be legal while 43 percent said it should be illegal. And if there is one thing politicians listen to, it’s polls. Polls reflect the public mood and its changes, and that affects who gets elected.

Same-sex marriage probably won’t be an issue in a generation, and it will be generally supported. But it is still an issue now. The question is, how big of an issue is it?

The difference in approach by the candidates is subtle for a reason. Keep the base, court the independents.

Will a candidate’s stance on same-sex marriage make a difference in how you cast your ballot for governor?

Locally, we have two seats in the state House of Representatives up this year. Will this issue play a role in which candidate you support? And if the issue of same-sex marriage is on the state ballot, as it likely will be, how will you vote?