The amendment approved 38-27 Wednesday sets the vote on whether to define marriage as between one man and one woman. That definition already exists in Minnesota statute, but supporters of the traditional definition of marriage say the extra protection is needed to guard against judicial rulings.

Critics of the amendment say it would enshrine discrimination in the state’s most important document and that it’s a distraction from more important issues facing the state.

Sen. Leroy Stumpf of Plummer was the only Democrat who voted yes. All Senate Republicans voted yes.

The state House has not yet voted on the gay marriage amendment but its passage is expected with Republicans in control of that chamber. Gov. Mark Dayton opposes the amendment, but governors are not able to block state lawmakers from putting constitutional amendments on the ballot.

It’s the first time the state Senate has approved the marriage amendment despite years of trying by socially conservative groups and their allies in the Legislature. The push got new life this year when Republicans took control of the chamber after decades of Democratic control.