COLUMBIA--The Senate Judiciary Committee approved a bill to let voters decide whether the state constitution should be changed to bar same-sex marriages, despite harsh criticism from Senate President Pro Tem Glenn McConnell that the measure is vague and unconstitutional.

"It's overreaching. It's constitutionally vague and it probably invades the right of contract," McConnell, R-Charleston, said after a 16-2 vote Tuesday. "It has not been thought out by this committee."

The amendment says marriage is "exclusively defined as the union between one man and one woman" and all other unions are void.

South Carolina already has a law that bars same-sex marriages, but supporters argue a judge could strike the law down and open the door to gay unions in the state.

The constitutional amendment has cleared the House and would be put before the voters in November 2006 if the Senate approves it.

McConnell joined Sen. Robert Ford, D-Charleston, in opposing the bill. "This ... bill is defective," McConnell told his colleagues after a discussion on the measure. "I'm not going to vote for it."

McConnell complained the bill does not define what a "union" might be, thereby confusing what constitutes contracts between men and women.

Ford criticized the measure as unnecessary, arguing the state has a law against same-sex marriage. "We have one of the strongest ones in the country," he said.

McConnell said he was offended by the rush to bring the measure to the floor of the Senate. Backers of the measure surprised the Senate several weeks ago by pulling it out of Ford's subcommittee.

After McConnell complained the move showed disrespect and lectured his colleagues on courtesy, the Senate sent the bill back to Ford's panel but also set a hearing for the full committee.