According to this Robert Novak column
[Gay marriage] is a yes-or-no choice for the president, with a middle course not possible. Without a constitutional amendment, gay marriage will become part of the fabric of American life. Bush must decide, therefore, whether that is truly important. Christian conservatives who support him say that it is, transcending abortion in shaping the country's culture.
So, people who believe that abortion is exactly the same as killing an infant think that the state recognizing a contract between two strangers is worse?