HOUSTON (Reuters) - Texans voted overwhelmingly to add a prohibition of same-sex marriage to their constitution on Tuesday, becoming the 19th U.S. state to do so.
With about 550,000 votes counted, Proposition 2 was heading for ratification with 75.5 percent in favor.
The outcome was expected even by opponents and continued a backlash to the movement for same-sex marriage that seemed to gain momentum when a Massachusetts court legalized gay unions in 2004.
Since then, same-sex marriage has suffered a string of losses at the polls as citizens elsewhere have rejected the notion.
Texas was the only state with such a measure on the ballot. The home state of President George W. Bush already had a law barring gay marriage but proponents of the measure, mostly Republicans, sought a constitutional amendment to block a possible court challenge similar to the one in Massachusetts.
The opposition, largely Democratic, argued the amendment was unnecessary and worded so broadly that it could infringe on existing rights of homosexuals, like their ability to visit a gravely ill partner in the hospital.
Several other states have laws, but not constitutional language, defining marriage as being between a man and a woman.
Bush and some Republicans have sought an amendment to the U.S. Constitution barring same-sex marriage, but the effort has yet to gain traction.