Next week’s special election in Iowa could jeopardize the state’s same-sex marriage rights if a Republican candidate wins and overturns Democratic control of the upper chamber of the legislature.

In an election set for Tuesday, Democrat Liz Mathis, a former news anchor for an Iowa TV station, and Republican Cindy Golding, a businessperson, are competing to represent Iowa’s 18th District in the state Senate. The vacancy was created by the retirement of Democratic former State Sen. Swati Dandekar, who left the Senate for an appointment in Republican Iowa Gov. Terry Branstad’s administration.

Senate Majority Leader Michael Gronstal (D) has vowed that a state constitutional amendment overturning marriage equality — instituted in 2009 in Iowa by order of the state Supreme Court — won’t come up as long as he remains leader of the chamber. But Democrats hold a majority in the state Senate by a margin of 25-24, so a win by the Republican would make for a tie in the leadership vote and throw control of the chamber into question.

The Democratic and Republican candidates have taken opposite positions on a constitutional amendment that could overturn marriage equality in Iowa. During an interview Monday with the Cedar Rapids Editorial Board, Mathis said she supports marriage equality, while Golding called for bringing the issue to the voters.

Mathis said she agrees with the Iowa Supreme Court ruling and said she doesn’t “believe in discrimination.”

“I believe in the Iowa State Supreme Court, their unanimous ruling, appellate ruling on gay marriage,” Mathis said. “Varnum v. Brien is constitutionally sound. And I’ll just leave it at that.”

Golding, on the other hand, reiterated her belief that the “citizens of Iowa should vote on this issue.”

“I believe that once we vote on it, whether we vote it up or down, the spotlight can come off Iowa for that issue and we can focus on business, we can focus on jobs, focus on education,” Golding said. “We can focus on the things we really need to be taking our time and energy. Because nobody in our district, it was not a huge issue to either one of us as we were going around. It became an issue to us by the national media.”

Golding continued that while she doesn’t believe the ruling has “dramatically changed” Iowa, she does believe the decision has affected schools. She took issue with what she said was scholarships for LGBT students at her daughter’s high school.

“I am curious what the sexual orientation of a student should be for a scholarship in high school,” Golding said. “That troubles me.”

Asked whether there are other criteria for the scholarship, Golding replied, “Well there’s academics, but you must be a declared GLBT student in order to apply for it. That troubles me.”

The plan for Senate leadership if the election results in a tie between the number Democrats and Republicans in the chamber remains in question. During a previous tie in 2005 and 2006, Democrats and Republicans alternatively shared power in the Senate and a rule was put in place ensuring no legislation could come up without consent of both parties. But Price said Republican Leader Paul McKinley has said he won’t agree to such a rule this time around.

In February, the Iowa House passed a constitutional amendment banning same-sex marriage, or even marriage-like unions. For the measure to come to the voters, it would need to first make it through the Senate before the term of the legislature expires. The measure would then have to pass both chambers of the General Assembly again in a separate session with the same language. The soonest the constitutional amendment could come before voters is 2013.

LGBT advocates in Iowa called a Democratic win in the election crucial to preserving marriage equality in Iowa as well as preventing other conservative initiatives from moving through the legislature.

Troy Price, executive director of One Iowa, said a Republican victory could remove the last barrier in the state legislature preventing the passage of a constitutional amendment banning same-sex marriage.

“We could see this thing on the ballot in less than two years,” Price said. “For us, this election means quite a bit, and that’s why we’re working so hard to try and protect and maintain the pro-equality majority in the Senate.”

State Sen. Matt McCoy (D), the first openly gay person elected to the Iowa Legislature, said the election is “very crucial” for marriage equality and the progressive agenda.

“This is a must-win election as it relates to marriage equality,” McCoy said. “Obviously, civil rights for tens of thousands of people are at stake, and in addition to that, I think all the other right-wing social agenda issues are potentially at stake as well. So we could see a completely different agenda: less focus on education, less focus on human services, less focus on growing our economy and jobs and more focus on right-wing fringe political issues and agendas.”

According to the Daily Iowan, the district in question is about evenly split between Democrats and Republicans.

Price said he’s “cautiously optimistic” about a Democratic win.

“Things are looking up there from our perspective,” Price said. “We’ve been working really hard. We’ve been identifying new marriage supporters in the district and trying to do everything we can to get those people out to the polls.”

McCoy also expressed confidence in Mathis’ ability to win the election and said her supporters are “spending enormous amounts of money” to ensure she wins.

“We feel very confident that we have an excellent candidate who’s working very hard and is doing all of the right things at this point to ensure that we can win this election,” McCoy said. “So, we feel very comfortable that this is a seat we can win and hold.”

The election has also come to the attention of national groups — both pro-LGBT and anti-gay — working on the issue of marriage. The National Organization for Marriage, which opposes same-sex marriage, announced last month that it would conduct an independent expenditure campaign — along with the Family Leader, a local anti-gay group — to assist Golding with her campaign.

Brian Brown, NOM’s president, called the race a “pivotal election contest” in the effort to bring marriage rights for gay couples before the Iowa electorate.

“A proposed constitutional amendment on defining marriage as the union of one man and one woman enjoys broad-based, bipartisan legislative and voter support, but is being prevented from coming to the floor of the Senate by Majority Leader Mike Gronstal,” Brown said. “If Ms. Golding is successful in her election, we are hopeful that senators will finally have the opportunity to vote on the marriage amendment, and we expect it to pass handily.”

Among NOM’s efforts is the distribution of a mailer featuring pictures of both Mathis and Golding on opposite sides on the Scales of Justice. Mathis is pulling the scale down on her side. The caption below Mathis reads, “Liz Mathis supports gay marriage; No vote of the people.” The caption below Golding reads, “Cindy Golding supports traditional marriage; Will let the people vote!”

But NOM’s involvement reportedly hasn’t stopped there. Price said he’s heard anecdotally NOM is “knocking on doors” in the district and is set to hold an event on Sunday as part of a national press tour.

“We are aware that this is on their radar screen … so we’re doing everything we can to try and counteract that,” Price said.

Pro-LGBT national groups are also involved in the election on behalf of the Democratic candidate. Price said the election is “definitely on their radar” as well, but couldn’t immediately name any of the national pro-LGBT groups that are involved. The Human Rights Campaign didn’t respond to a request for comment on the election.

“This election is really a local election from our perspective, so we’ve just been working with out local partners to make sure that the voice of equality is heard,” Price said.