All say the amendment goes too far and could affect couples of the same or opposite sex.

The Catholic Conference of Ohio said Wednesday it supports the measure.

"The Catholic Church believes and clearly teaches that marriage is a faithful, exclusive and lifelong union between one man and one woman," a statement released by Ohio's 14 Roman Catholic bishops said.

The amendment would ban gay marriage and also prohibit the state and local governments from giving a legal status similar to marriage to any unmarried couple.

Republican U.S. Sens. Mike DeWine and George Voinovich both say they are opposed to gay marriage but say the amendment's second clause raises too many unanswered questions.

Voinovich spokesman Scott Milburn said the senator is "concerned that it may interfere with organizations that receive state funds, such as public or even private universities, and he's concerned with how it may even interfere with what businesses do for any employee in terms of compensation and benefits."