These percentages are illustrated in Figure 3. Interestingly, research has demonstrated that the when public opinion is sought between "gay marriage" and "civil union" the results differed greatly. Although the rights being suggested were similar, when framed as gay marriage, the discussions became polarized along ideological lines, than when framed as civil unions ("Framing," n.d.). Clearly individuals were less threatened by the idea of civil unions than gay marraiges, even if the details of the two concepts were similar. However, Craig, Martinez, Kane, and Gainous (2005) found that many individuals were ambivalent to gay rights issues. With the polarized nature of gay rights, these researchers found that individuals most often had differing viewpoints depending on what the specific topic of gay rights involved, with both positive and negative opinions.

Figure 3: Public Opinion for Civil Unions

(Source: "A stable majority," 2008)

The Constitutional Right to Privacy and Gay Marriage:

Proponents of gay marriage insist that the right for gays and lesbians to marry is a matter of constitutional privacy. The Fourth Amendment to the Bill of Rights suggests the rights to individual privacy are important. It states that individuals have a right "to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized" ("Bill of Rights," n.d.). The Ninth Amendment too broadens this right of privacy by stating that the list in the Bill of Rights is not all inclusive. Numerous court cases, both directly related and indirectly related, have sought to determine just where an individual's right to privacy begins and ends. To date, gay marriage has not been found to be included in this broadly defined right to privacy....

Without this constitutional backing, and given the stable majority opinion against gay marriage, it is unlikely that gay marriage will become a nationally recognized institution.
Conclusion:

Although gay unions have been a reality for centuries, the American debate regarding gay marriage is a modern invention. There are several factors that play into the likelihood that civil unions between gay couples are far more likely to be accepted nationally, then gay marriage. The majority of Americans are against gay marriage. This has been a steady figure for several years and does not appear to be changing in the near future. An aging American population adds to this unlikelihood. Interestingly thought, a majority of Americans do favor gay civil unions and this number is increasing. Given the fact that there is no specific constitutional right to marry, it is unlikely that a federal law allowing gay marriage will occur. However, with increasing public support, civil unions may become an option for many states.