Why do same-sex marriage advocates describe marriage bans as discrimination?

Same-sex marriage advocates describe marriage bans as discrimination because they view such prohibitions as arbitrary and irrational, effectively creating a second class of citizens by denying same-sex couples access to the fundamental rights, benefits, and social support afforded to heterosexual couples.12

Advocates argue that marriage is a civil right protected by constitutional commitments to liberty and equality. By restricting this institution based on sexual orientation or gender, bans are seen as violating the equal protection and due process clauses of the U.S. Constitution. Furthermore, advocates emphasize that these bans deprive couples of over 1,000 federal legal protections—such as inheritance rights, hospital visitation, and tax benefits—which causes tangible economic, physical, and psychological harm.312

Ultimately, proponents maintain that because committed partnerships are intrinsically valuable to the stability of society, denying these legal perquisites to same-sex couples is a form of discrimination that contradicts the principle of equal treatment under the law.12