Should Gays have access to the same rights as heterosexuals?

Subject: U.S. Constitutional Question

I was recently challenged in my thinking regarding the 2008 Connecticut Supreme Court ruling regarding equality in marriage.

Are there times or situations in which society should withhold or deny legal rights to certain persons? For instance, should a convicted felon be denied the right to vote? (15th Amendment Right). Or, should felons be allowed to have guns? (Second Amendment Right).  I might venture to say that a person's behavior could create a legitimate basis for denying legal rights.

My challenge to the reader is this: Does Chief Justice Ronald M. George, writing the majority opinion, get it right when he wrote, “An individual’s sexual orientation — like a person’s race or gender — does not constitute a legitimate basis upon which to deny or withhold legal rights.”

I truly would like a thoughtful discussion to the following question: Is there a Constitutional Amendment that would be applicable, or, a reasonable interpretation, to support the denial or withholding of the legal right to marriage?