The resignation of Democratic State Senator Swati Dandekar could spell trouble for gay marriage in Iowa.

The Democrat-controlled Senate, under the leadership of Majority Leader Michael Gronstal, has kept an effort to repeal the law at bay. In February, the Republican-controlled House approved a measure that seeks to put a question on the ballot that would define marriage in the Iowa Constitution as a heterosexual union – and thereby reverse the 2009 Iowa Supreme Court ruling that brought gay marriage to the Midwest.

Gronstal has vowed to block the measure from reaching the Senate floor.

But Republican Governor Terry Branstad's appointment of Dandekar to the Iowa Utilities Board could result in Democrats losing their one-seat Senate majority. And by extension, stripping Gronstal of power. In previous sessions where the Senate was divided, leaders from both parties took turns on alternating weeks running the chamber.

A special election to fill the seat will be held on November 8. Dandekar's district predominantly votes Republican.

Democrats quickly went on the offensive, launching the Internet site

“This election will be a clear choice between what voters in the district want: someone who will stand up and support them in the Iowa Senate, or someone who will pursue a divisive agenda like Iowa Republicans chose to during the last session,” Iowa Democratic Chairwoman Sue Dvorksy told The Des Moines Register. “We're confident that Iowans will vote for real leadership and choose to maintain Democratic control of this seat.”