SALEM (AP) — Oregon Sen. Gordon Smith is apologizing for creating confusion by linking the debate over same-sex marriage to the persecution of his Mormon ancestors for practicing polygamy.

Smith’s comments, which came during a gay rights forum in Washington, D.C. last week, have become an issue in his re-election campaign. Democratic challenger Jeff Merkley’s campaign said at the time it appeared Smith was defending polygamy.

The Republican senator said in an interview Tuesday that he has always opposed polygamy — marriages in which a man has more than one wife, a practice Mormons no longer condone.

Further, he said polygamy and same-sex marriage are unrelated, and that he’s sorry he mentioned both in what he called his confusing comments about Mormon history.

“That reference was unfortunate, and I apologize for it,” Smith said.

Smith also said he continues to support protections for gays and lesbians, including Oregon’s new domestic partnership law, although his comments caused a stir among gay rights advocates.

A spokeswoman for Basic Rights Oregon, the state’s largest gay rights group, said Tuesday the organization was glad Smith issued a clarification of his comments.

At the same time, spokeswoman Karynn Fish said the group is still troubled by Smith’s support for a federal law that defines marriage as between one man and one woman.

“We think all committed couples should have the dignity and respect that come with full marriage rights,” she said.

Merkley’s campaign spokesman, Matt Canter, noted that Smith began last week’s remarks by saying, “My campaign people will kill me for saying this, but ...”

“What was he trying to say that his campaign people would kill him for?” Canter said. “Voters are going to have to make their own determination about what Sen. Smith really thinks. He is saying different things to different audiences.”

Smith, in last week’s panel discussion, said his Mormon ancestors were victims of attempts to define marriage. While he supports arrangements like domestic partnerships for same-sex couples, he remains firm in his belief that marriage should be between one man and one woman.

“My remarks referenced a point in time when some of my ancestors were persecuted for not adhering to that belief” and practicing polygamy instead, Smith said. “I was asked a very personal question, and I gave a very personal answer. And my answer missed the mark.”