Social conservatives are targeting Iowa State Senate President Jack Kibbie for not backing a constitutional amendment that would define marriage as a heterosexual union, Radio Iowa reported.

The Iowa Family Policy Center, the state's most vociferous opponent of gay marriage, is criticizing Kibbie for not pressing harder for the amendment, which, if approved by voters, would trump the Iowa Supreme Court's 2009 unanimous ruling legalizing gay marriage.

The group's “Let Us Vote” (LUV) campaign focuses on pressuring state lawmakers to send the amendment to the ballot box. The group is angry that Democratic leaders have blocked passage of the measure, which needs the approval of the General Assembly before heading to voters.

On the Internet – – and on billboards and fliers, the group is accusing the president of back-peddling on the issue.

“There is one senator in north central Iowa who is getting sick and tired of LUV Iowa, I want to tell you that right now,” Tom Nichols, a LUV Iowa member, told a crowd last week in Des Moines. “For those of you who want to write it down – He's got a little video up about him. He's going to have some more in a couple of days. We're going to keep reminding him that he said he was in support of marriage and family and he ain't doing nothing about it.”

LUV Iowa wants Kibbie, a Democrat who has publicly stated his opposition to gay marriage, to join a group of mostly Republicans in wrenching the amendment resolution out of committee and bring it to the Senate floor for a vote. A procedural maneuver that has already failed in both chambers.

Kibbie, however, says such a motion would only place the issue on the Senate's debate calendar and Senate Democratic Leader Mike Gronstal, who controls the agenda, has repeatedly said he will not allow a vote on the issue this year.

“I understand where they're coming from,” Kibbie said. “As president of the Senate they think I have the authority and the power to control that agenda, which I don't have.”

Opponents of gay marriage have vowed to make repeal an issue during the 2010 mid-term elections.