Sen. Lindsey Graham (R-SC) says that the United States Supreme Court should not rule that LGBT couples have the right to marry because it is like banning slavery and should require a constitutional amendment.

"When is it proper for the government to set boundaries in terms of relationships?" Graham opined to CNN's Piers Morgan on Tuesday. "It's clearly proper to say you can't kill someone. And I have no problem with people passing on their property to someone they love. I have no problem with people having the ability to -- to engage in a free and open life."

"A lot of this is religious. In my state, we're not going to change the traditional definition of marriage. And I would support the traditional definition of marriage, not out of a hate, but if I believed it, I think that's just best for society. At the end of the day, states will come out differently on this issue. And I think that's the way it should be."

But Morgan wondered if America could "really stand for freedom and genuine equality if half the states continue to view the rights of a homosexual couple to get married in a completely different way?"

"I'm sorry, but here's a country that stands on the grounds of freedom, democracy and equality. And here you are all telling me that's fine, as long as you're in the right state," Morgan observed.

Sen. John McCain (R-AZ), who also participated in the interview, pointed out that the "Constitution of the United States says all rights are reserved for the states except for those given to the government."

"Would you respect the original rights of the founding fathers to allow slavery?" Morgan wondered. "Would you allow slavery in some states but not others?"

"Can I suggest this?" Graham offered. "Slavery was outlawed by a constitutional amendment. Go watch 'Lincoln,' a great movie. The people decided. The question for us is who should decide these things? Should it be a handful of judges or should it be the people themselves? And I come out on the side of the people themselves."

"But slavery was outlawed by a constitutional amendment," he continued. "If you want to propose a constitutional amendment legalizing same-sex marriage and it passes, that's the law of the land."

Graham's logic, however, ignores that discrimination was enshrined into the Constitution with the Three-Fifths Compromise, which said that slaves only counted as three-fifths of a person. President Abraham Lincoln's Emancipation Proclamation declared that slaves in rebelling states were free, but it was not until after as many as 620,000 people died in the American Civil War that states ratified the 13th Amendment, that slavery was outlawed and the three-fifths compromise was rendered moot.

The Fourteenth Amendment later guaranteed equal protection under the law to all people. Civil rights activists maintain the Equal Protection Clause of the Fourteenth Amendment should also prohibit government from banning same sex marriage.

Watch this video from CNN's Piers Morgan Tonight, broadcast Dec. 12, 2012.

(h/t: Think Progress)