WINONA, Minn. -

Minnesota voters will decide Tuesday whether their constitution will define marriage.

They will vote on an amendment to define marriage as between one man and one woman.

Same-sex marriage is already banned in Minnesota, but that law could be overturned by the legislature or by a judicial ruling. Having it as an amendment to the state constitution would make it a lot more difficult to legalize same-sex marriage.

A recent Star Tribune poll shows Minnesota voters are split in a dead heat, with 48 percent in favor of the amendment and 47 percent opposed.

Winona resident JamieAnn Meyers knows what she wants for her 46th wedding anniversary on Tuesday. She wants Minnesota to vote no on the constitutional amendment.

"That would be one of the biggest gifts that we could have on our anniversary," said Meyers.

JamieAnn wasn't always JamieAnn.

"James was my birth assigned name," said Meyers.

She's got another important anniversary coming up too. On Nov. 16 eight years ago, she came out to her wife, Peggy Meyers, that she was struggling with her gender identity.

"I was afraid of losing everything in my life. I was afraid of losing Peggy, my children, my parents, my friends, my job, my house, my respect of my students. Everything," said JamieAnn Meyers.

But she didn't lose everything. Meyers and her wife have remained married throughout the transition.

She said their situation proves defining marriage as between one man and one woman isn't always as clear-cut as it might seem.

"Does that mean that the marriage is no longer valid? It is valid. It's valid in the eyes of the law. It's valid in the eyes of God," said Meyers.

The Star Tribune poll shows 70 percent of likely voters who plan to vote in favor of the amendment said their faith leaders had an impact on their decisions.

But Winona resident Mac McCauley said religion has nothing to do with his decision to vote yes.

"No, just common sense," said McCauley.

He has no issue with same-sex couples having the same rights. For him, it's a matter of tradition.

"I don't agree with them calling it a marriage. They can have their rights, but it's not a marriage because, for thousands of years, it's been man and woman,” said McCauley.

If the amendment does pass, the only way to legalize same-sex marriage at the state level would be another statewide vote to remove the amendment from the constitution. A federal law or court ruling could have the same effect.

If the amendment does not pass, the state's 1997 Defense of Marriage law banning same-sex marriage would still be in effect.

Thirty states have amended their constitutions to limit marriage rights to only heterosexual couples.