The notion of equal protection assumes a guarantee granted to individuals by the Fourteenth Amendment to the U.S. Constitution. The Amendment safeguards equal treatment to all individuals in like circumstances. This indicates that according to the Constitution no person shall be denied equal protection enjoyed by other persons. The definition alludes to the Declaration of Independence proclaiming the equality of all men subject to the inalienable rights for life, liberty and happiness.

The same-sex couples have the same rights to marry as the opposite-sex couples do. This makes the marriage rights fundamental pursuant to the Fourteenth Amendment of the United States Constitution. The nationwide recognition and performance of the same-sex-couple marriages proves the freedom of choice and non-discrimination in the democratic and liberal society.

Lawrence v. Texas was the pivotal 2003 6–3 decision passed by the Supreme Court to void sodomy law in Texas and further 13 other states. Consequently, the ruling protected sexual privacy of individuals by legalizing the sexual activity of the same-sex couples across the United States. The Court appealed to the Fourteenth Amendment to acknowledge intimate sexual conduct among fundamental liberties guaranteed by due process. Lawrence overruled Bowers pointing at its rather narrow interpretation of liberty interest. By voiding the laws criminalizing sodomy, the resolution was fully in line with the Fourteenth Amendment. Regardless of the sex of the partners, they were now free to act whatever they wanted in their private relationships. The Lawrence v. Texas served as a solid background for the forthcoming Supreme Court resolution in Obergefell v. Hodges advocating the fundamentality of same-sex marriages.

The Defense of Marriage Act (1996) is the US federal law (now deemed unconstitutional) defined federal status of marriage solely on the grounds of heterosexuality. By default, the Act banned same-sex marriages. This meant that federal law did not defined same-sex partners as legal ‘spouses’ and assumed beneficiaries of the federal marriage benefits. The Section 3 of the Act failed to recognize same-sex marriages depriving the same-sex partners of such essential federal benefits as insurance, social security, and joint tax returns. Regardless of the federal legislation, some states managed to recognize same-sex marriages. Still, even being married legally in compliance with the state laws, the same-sex couples were deprived of the marriage benefits.

In 2013, the ruling in the United States v. Windsor case unrecognized same-sex married couples. The Supreme Court ruled Section 3 of the Act as unconstitutional. Further, Obergefell v. Hodges 2015 legalized the same-sex marriages under federal jurisdiction. This way the Act and the court cases acknowledged Due Process Clause compatible with the context of the Fifth Amendment to the US Constitution.

The June 26, 2015 judgment in Obergefell v. Hodges marks the landmark civil rights ruling by the US Supreme Court. The ruling entitles the same-sex couples to marry just in the same manner (in like circumstances) as the opposite-sex couples do. The ruling appeals to the Equal Protection Clause and the Due Process Clause envisaged by the Fourteenth Amendment. From then on, all fifty states recognize the validity of and perform the same-sex-couple marriages across the United States on the grounds of marriage licenses. This way, the United States has achieved ultimate guarantee of fundamental rights protection and suppressed the instances of inequality and discrimination.

The analyzed court decisions in equal protection cases proved democratic and liberal status of the United States which Constitution safeguards equal treatment to all individuals in like circumstances (Fourteenth Amendment) and protects individuals from being “deprived of life, liberty, or property, without due process of law” (Fifth Amendment).