Updated

The Texas Senate (search) approved a proposed constitutional ban on same-sex marriage with a 21-8 vote Saturday, sending the issue to voters.

Last month, the House (search) narrowly passed the proposal, which would define marriage as between one man and one woman.

State law already prohibits same-sex marriages. If approved in a statewide vote in November, Texas (search) would join 14 states that statutorily and constitutionally ban same-sex marriage. Massachusetts is the only state that allows such marriages, although Vermont and Connecticut have approved same-sex civil unions.

Opponents have criticized the ban as discrimination against gays and lesbians and warn it could harm heterosexual families if domestic partner benefits, powers of attorney and common law marriage are called into question.

Sen. Todd Staples, R-Palestine, who sponsored the legislation in the Senate, said none of those scenarios would be affected and would not prevent same-sex couples from adopting children. The House has voted to ban gays from becoming foster parents, but that measure has received little support in the Senate.

Staples rejected arguments the amendment would discriminate against gays and lesbians and the estimated 43,000 same-sex couples in Texas.

Sen. Rodney Ellis, D-Houston, equated the amendment to Jim Crow-era laws that discriminated against blacks.

"At least they had the good sense to never write their bigotry into the state Constitution," said Ellis, who called the amendment "trash."

Staples said he is offended by accusations the amendment is anti-gay.

"There's a distinction between intimate associations and the right to have the government recognize or subsidize your arrangement," Staples said.