Lawmakers in Massachusetts are considering an amendment to the state constitution, and Press Secretary Scott McClellan says the White House is watching closely.
In his State of the Union speech, the president declared that if "activist judges" don't stop meddling in the issue, "the constitutional process" may be the only option to defend the sanctity of marriage.
Conservative groups say the White House has told them Bush has already decided to back an amendment. But McClellan says administration lawyers are still reviewing the issue.
However, he says if Bush does agree an amendment's needed, he could support recently introduced wording that, according to backers, bars gay marriage, but permits civil unions.