"The federalism proposed by the liberal opponents of a constitutional amendment is in fact a sham" (Robert George and David Tubbs, 2014)

Prophetic words in 2004 from Princeton University legal scholar Robert George and David Tubbs: http://www.city-journal.org/html/14_4_marriage_amendment.html :

• "When President George W. Bush declared his support for a federal constitutional amendment defining marriage as the union of one man and one woman, his most vitriolic critics, such as Senator Edward Kennedy, accused him of playing a divisive, mean-spirited political game. The New York Times and Washington Post, supporters of the idea of same-sex marriage, raised a more sophisticated objection to the amendment: it betrays, they claim, the venerable principle of American federalism that respects states' relative autonomy in setting marriage policy. Interestingly, some prominent conservative opponents of same-sex 'marriage'...were also skeptical about the amendment on federalism grounds. State voters could and would prevent the imposition of same-sex marriage, these critics argued. There was no need to nationalize the issue.

• "Despite its widespread appeal, the states' rights solution won't work. Without a federal marriage amendment, we're going to wind up with same-sex marriage in all 50 states. And here's why.

• "The federalism proposed by the liberal opponents of a constitutional amendment is in fact a sham. It is a contrivance for permitting liberal state judges, abetted by sympathetic justices on the Supreme Court of the United States, to foist same-sex marriage upon the whole nation....

• "Regrettably, ...state-level political efforts ultimately won't stop the march to redefine marriage [That is NOT to say that those efforts should be abandoned.].  The reason: the Supreme Court is almost certain to nationalize the issue and make same-sex-marriage legal from coast to coast....

• "Will a Supreme Court...that has refused to accept state differences in laws on contraception or abortion-indefinitely tolerate a federalist approach to marriage policy? It's extremely unlikely....

• "Were it not for judicial overreach, we would not be having a national debate on same-sex marriage. That we are having one raises troubling questions about the condition of democratic self-government in America today. For defensive reasons, therefore, we need a federal marriage amendment."

Fast Forward to 2014 and USCCB-backed Efforts to Protect Marriage on a Federal Level

HJ Res 51 - As per Archbishop Cordileone's 2/19/14 letter to Representative Tim Huelskamp,

• "As the Chairman of the U.S. Conference of Catholic Bishops’ Subcommittee for the Promotion and Defense of Marriage, I write in strong support of your resolution, H. J. Res. 51, the Marriage Protection Amendment to the U.S. Constitution....Recently, a number of federal courts have ruled against the constitutionality of state marriage laws that honor the reality of marriage as the union of one man and one woman....An amendment to the U.S. Constitution is the only remedy in law against this judicial activism that may ultimately end with federal judges declaring that the U.S. Constitution requires states, and consequently the federal government, to redefine marriage. Just as Roe v. Wade mandated a constitutional right to abortion throughout the country, we now have the possibility of another bad decision mandating a constitutional change in the meaning of marriage....I am, therefore, very pleased to support the Marriage Protection Amendment and urge your colleagues to join H. J. Res. 51 as cosponsors" (http://www.usccb.org/issues-and-action/marriage-and-family/marriage/promotion-and-defense-of-marriage/upload/Ltr-to-Huelskamp-re-MPA.pdf)

HR 3133 - As per the USCCB's "Marriage and Religious Freedom Act Backgrounder",

• "The
  M MarriageMarriage and Religious Freedom Act (H.R. 3133, S. 1808) would bar the federal government
  from discriminating against individuals and organizations based upon their religiously-motivated
  belief that marriage is the union of one man and one woman or that sexual
  relations are properly reserved to such a marriage....The
  Act is needed because of growing intolerance toward religiously-minded
  individuals and organizations who want to live by their conviction that
  marriage is the union of one man and one woman or that sexual relations are
  properly reserved to such a marriage....In
  light of... government action against those who believe
  that marriage is the union of one man and one woman or that sexual relations
  are properly reserved to such a marriage, it is vital that Congress act now to
  prevent similar intolerance at the federal level" (http://www.usccb.org/issues-and-action/marriage-and-family/marriage/promotion-and-defense-of-marriage/marriage-and-religious-freedom-act-backgrounder.cfm).

HR 3829 - As per Archbishop Cordileone's 1/10/14 letter to Representative Randy Weber, 

• "I am...very pleased to support the State Marriage Defense Act of 2014 and urge your colleagues to join H.R. 3829 as cosponsors" (http://www.usccb.org/issues-and-action/marriage-and-family/marriage/promotion-and-defense-of-marriage/upload/Ltr-to-Weber-re-SMDA.pdf).