Gail Burton, Associated Press
Senate President Thomas "Mike" Miller, D-Anne Arundel Co., listens to arguments on the gay marriage bill on the state Senate floor Thursday, Feb. 24, 2011 in Annapolis, Md. Miller is opposed to the bill.

ANNAPOLIS, Md. — With Maryland senators poised to pass a measure legalizing gay marriage, debate grew personal Thursday as lawmakers spoke of family members in explaining their positions.

State senators late Thursday are expected to give final approval to a bill that would legalize gay marriage. The bill, if then passed by the House and signed by Gov. Martin O'Malley, would grant same-sex couples full marriage rights in Maryland.

The Senate's only openly gay member, Sen. Richard Madaleno, D-Montgomery, told his colleagues Thursday that his partner — whom he married 10 years ago — is still a "legal stranger" to him in Maryland.

"This bill is quite simple, it has two parts to it: It reiterates that no religious denomination will ever be required to recognize, perform or celebrate any marriage that is against its beliefs. At the same time, it provides full equality under the law for thousands of same-gender couples in our state, couples like Mark and myself," Madaleno said.

Senators modified the bill to add protections for religious groups and institutions to keep them from being forced to participate in gay weddings. But the core measure — granting the same title and rights to same-sex couples that Maryland grants to married straight couples — is the same.

If the measure becomes law, Maryland would become the sixth state to approve gay marriages. Senate President Thomas V. Mike Miller said this month he felt the push toward more rights for gay men and women is part of a national trend.

Hawaii approved civil unions for same-sex couples Wednesday, the same day the Obama administration told Congress it would stop opposing legal challenges to the federal law that defines marriage as being between one man and one woman. Illinois legalized civil unions for same-sex couples last month.

In the Maryland Senate Thursday, the debate — while hardly vitriolic or heated — was still deeply personal.

The only Republican to support gay marriage, Sen. Allan Kittleman, R-Howard, recalled his father's work with the black community during the civil rights movement. Kittleman, who is white, said his father would invite leaders from the NAACP and other civil rights groups to his house when he was growing up in the 1960s.

"We lived in a very white neighborhood, and we'd have the leaders of the African American community coming to our house talking and I would go to my neighbors' later, I'd go see my friends and their parents would come to me and say 'Allan, why do all those black people come to your house?'" Kittleman said.

Granting full marriage rights to same-sex couples might not be the same as the civil rights movement, Kittleman said, but "it's the right thing to do."

But Sen. Joanne Benson said her father — who was a "civil rights warrior" and a friend of Kittleman's father — taught her that marriage can only be between one man and woman.

"My father often talked to us about the importance of marriage," said Benson, D-Prince George's. "One thing he said to us was you get married because one of the most important reasons for marriage is to have children."

Opponents argued this week that Maryland children might be forced to read books like "King and King," a children's book about two gay princes. Parents in Massachusetts sued a local school system after the book was read to second-graders in 2006.

"Yes, this bill affects homosexual individuals wanting to marry. But as we've seen in other states, it also affects young impressionable students in our school system who are taught the homosexual world view," said Sen. Bryan Simonaire, R-Anne Arundel and the father of seven children.

Sen. Delores Kelley, D-Baltimore County, rebutted religious arguments from opponents. She recounted how her younger sister, while in medical school, helped deliver a child who was "clearly not of a specific gender."

The experience, as doctors decided whether to conduct surgery on the baby, was "traumatic" for her sister, Kelley said.

"I think that there are many mysteries in life that none of us is smart enough to totally fathom: why we are as we are, why others are as they are. I think we've got to respect that none of us is the creator and none of us really knows," she said.