It would have banned same-sex marriage in the United States. But instead, the Senate has scuttled the proposed amendment to the constitution that would have defined marriage as between a man and a woman. The vote was 50-48, ten short of the 60 needed to keep the measure alive.

Republican Rick Santorum said preserving traditional marriage was the ultimate form of "homeland security." But Democrat Tom Daschle said there was no "urgent need" for a constitutional amendment.

South Carolina Republican Lindsey Graham voted for the amendment. The state's other senator Democrat Fritz Hollings voted against it.

Two senators did not vote on the amendment. They were John Kerry and John Edwards. They are the likely nominees on the Democratic presidential ticket in November.

Supporters of the amendment vow to keep the issue alive.