LANCASTER COUNTY, PA - The state Senate Wednesday approved a proposed amendment to the state constitution that would define marriage as a man-woman union, but some of its supporters might consider it a defeat.

Senators, on a 38-12 vote, passed an amendment that is different than one the House approved earlier this month. Because the amendments passed by the two chambers are different, it could delay by two years a voter referendum on the measure.

The Senate amendment reads: "Only a marriage between one man and one woman shall be valid or recognized as a marriage in this Commonwealth."

The House version includes a provision some say not only bans gay marriage but also outlaws other domestic partnerships, such as civil unions.

State Sens. Gibson E. Armstrong and Noah Wenger -- both Lancaster County Republicans -- approved the Senate version Wednesday.

Armstrong said it was not an easy vote to cast.

"Bottom line is, by voting for the watered-down amendment, we still have a chance to keep things going," Armstrong said.

Wenger said voting against the Senate version would have had devastating consequences for the proposed amendment.

"Had we voted against that, the bill would have been dead," he said. "This keeps the issue alive and an opportunity for further debate and further amendment and whatever might happen."

The House version passed June 6 by a 136-61 vote, but the Senate Judiciary Committee stripped the provision about domestic partnerships, with one Republican arguing it was unnecessary and confusing to constitutional scholars and voters.

State Rep. Scott Boyd -- the Lampeter Republican who was the House bill's prime sponsor -- has argued the extra language is essential in the event of a court challenge against the amendment.

The Senate's action could undermine the amendment and push back voter approval to 2009, Boyd has said.

Boyd was not available for comment Wednesday night.

He has said without the House's provision a gay couple could receive a civil union license in another state, where it is lawful, then return to Pennsylvania to challenge the watered-down marriage amendment by pointing to the U.S. Constitution's 14th Amendment.

That amendment -- championed after the Civil War by 19th century statesman Thaddeus Stevens of Lancaster -- protects the equal status of citizens across state lines.

The bill now goes to the House, and if House members reject it, they can call for a legislative panel to draw up a compromise.

To amend the state constitution, the House and Senate would need to pass identical bills in consecutive legislative sessions, and the amendment would be put to a voter referendum.

Dave Pidgeon's e-mail address is dpidgeon@lnpnews.com.