All of Iowa's House faces re-election in 2010, as do some senators and Governor Culver, now in his first term.

Mr. Culver, who says he personally believes marriage should be between a man and a woman, said he was unlikely to support a constitutional amendment. "After careful consideration and a thorough reading of the court's decision," he said, "I am reluctant to support amending the Iowa Constitution to add a provision that our Supreme Court has said is unlawful and discriminatory."

The statement was seen by some as a shift. In 2008, Mr. Culver told reporters that he would wait for the courts to rule on same-sex marriage in Iowa but that lawmakers could then react quickly.