text: He has opposed the Federal Marriage Amendment, which would amend the US Constitution to define marriage as the union of one man and one woman, because he worries that with its passage "liberal social engineers who wish to use federal government power to redefine marriage will be able to point to the constitutional marriage amendment as proof that the definition of marriage is indeed a federal matter!  I am unwilling either to cede to federal courts the authority to redefine marriage, or to deny a state's ability to preserve the traditional definition of marriage."
  Paul has been a cosponsor of the Marriage Protection Act in each Congress since the bill's original introduction. It would bar federal judges from hearing cases pertaining to the constitutionality of the Defense of Marriage Act. Speaking in support of the Marriage Protection Act in 2004, he urged those of his fellow congressional representatives who "believe Congress needs to take immediate action to protect marriage" to vote for the bill because its passage, requiring only simple majorities in both Houses of Congress, would be much more readily achieved than the passage of the Federal Marriage Amendment, which, as a Constitutional amendment, would require not only much larger majorities in both Houses but also ratification by the state legislatures.