I'LL shortly introduce legislation that would legalize same-sex marriage in Pennsylvania, for several reasons.

Many states are moving on the issue: Maine, Vermont, D.C., New York, New Hampshire and New Jersey. A bill banning same-sex marriage was recently introduced in the Pennsylvania Senate, and it's important to provide a pro-civil-rights, pro-family alternative. But, mostly, each day that gay Pennsylvanians are denied their rights is a profound injustice.

The case for same-sex marriage is simple. The state and federal government confer hundreds of benefits on married couples that are unavailable to single people. This encourages marriage, which benefits society. We should be doing with gay couples what we do with straight couples: encouraging them to enter permanent, monogamous, stable, legally recognized unions.

The arguments against gay marriage are more complicated.

We're told we need to "protect traditional marriage." But what's happened to straight couples in states where gay couples can marry? Studies show straight-marriage rates remain the same. So do divorce rates, birth rates and domestic violence. There's no change in the status, behavior or happiness of married heterosexual couples when a married gay couple moves in down the street.

We hear that some organizations that disapprove of gay marriage might opt out if they are allowed. In Massachusetts, a Catholic adoption agency didn't want to provide adoptions to gay couples and closed.

This argument is akin to the "heckler's veto." Some have tried to ban certain speech by saying it would upset listeners who'd cause a disturbance: For example, it was said that if civil-rights activists were allowed to gather, protesters might riot. But courts have consistently rejected the argument that threats based on disapproval were a justification to ban speech.

We also hear that if we legalize gay marriage, we'll have no choice but to legalize polygamy, incest and interspecies marriage. Not so. We draw reasonable lines all the time in all areas of the law. You can drive 65, but not 95. You can keep a gun, but not a truck bomb.

It seems reasonable that the line should be drawn where it allows each person the opportunity to have a life partner.

There is no reasonable alternative to same-sex marriage. Same-sex couples will always exist. Many are raising children. Many opponents of gay marriage preach that children shouldn't be raised out of wedlock, but the one sure way to raise the number of children being raised out of wedlock is to deny their parents the chance to marry. They also urge young people to delay sex until marriage. But if gay people can't marry, what would they tell a gay teen about when it is appropriate for him to have a sexual relationship?

Gay couples are denied many of the basic rights and services straight couples take for granted. This includes everything from Social Security survivor benefits to mandatory leave to care for a sick partner.

FURTHER, they and their children are forced to live under a legal framework that treats their families as somehow not legitimate.

There are literally thousands of such unjust burdens placed upon people who want nothing more than to start a family. Simple decency demands an end to this.

I'm under no illusions that this bill will become law in the short term. But I also have no doubt that 15 years from now, same-sex marriage will be legal in all 50 states, and people will be as ashamed that we ever banned it as they are now that we ever banned interracial marriage. My hope is that by introducing this bill now, we'll start the discussion to bring the day of equality closer. *

State Sen. Daylin Leach, a Democrat, represents the King of Prussia area.