The measure has cleared the Republican-controlled House and is expected to win approval in the GOP-led Senate.
Indiana already has a statute on the books banning gay marriage, but Kent Smith of the Indiana Family Institute told the Senate Judiciary Committee that it needs protection from what he calls activist judges.
“Our goal with this amendment is simply to elevate marriage into our highest law, so that the citizens, who, as it’s been noted, own the Constititution, and not judges, will define what marriage is,” he said.
Opponent Jessica Welch said passage of the measure would send a message of intolerance.
“You will go down in history as becoming a road block to the future of this state,” she told lawmakers.
The committee will vote on the measure in a week. If it clears the legislature this year, it must again be approved by the next General Assembly and by voters in 2014 in order for the Constitution to be amended.