The amendment, House Joint Resolution 6, passed by a vote of 62-37, and would prohibit not only same-sex marriage, but also civil unions and domestic partnerships.
“The proposed amendment devalues families and divides Iowans,” said Carolyn Jenison, Executive Director of One Iowa, the state’s largest LGBT advocacy organization.
“The Constitution is meant to protect the freedoms and liberties of all Iowans. It is inappropriate to use the political process to single out and deny a group of Iowans of their constitutional protections,” said Jenison.
The bill now moves on to the Iowa Senate, where Senate Majority Leader Mike Gronstal has vowed to fight attempts to pass the amendment.
The measure must be approved by both houses of the Iowa legislature in two consecutive legislative sessions before being put up for referendum.
If passed by the Senate, the issue could be on the ballot as soon as 2013, but if Gronstal is successful in blocking a Senate vote this year, the earliest it would go before voters would be 2014.
At a public hearing Monday night, dozens of citizens lined up to speak for and against the marriage amendment, including one impassioned, well-spoken son of gay parents, and a former three-term state senator who said his previous support for a constitutional amendment banning same-sex marriage was misguided.
Civil rights advocates have blasted the proposed resolution as nothing more than writing prejudice and discrimination into the constitution.
Supporters of the amendment said Iowans should have a chance to vote on whether to allow same-sex marriage.
In 2009, the Iowa Supreme Court ruled unanimously that denying same-sex couples the right to marry violated the equal protection clause of the Iowa Constitution.
In June 2010, fourteen months after the Iowa Supreme Court ruling, a KCCI-TV poll found 53% of Iowans favored marriage rights for same-sex couples, while 41% were opposed.
An earlier Des Moines Register Iowa Poll said 62% of Iowans felt lawmakers had more important things to worry about than same-sex marriage.