Connecticut Supreme Court justices on Monday grappled with the question of whether sexual orientation should be viewed on virtually the same high level as race, religion and country of origin when deciding whether the denial of marriage licenses to same-sex couples violates the state constitution’s equal protection clause.

Attorney Bennett H. Klein, arguing on behalf of eight gay and lesbian couples seeking the right to marry in Connecticut, told the en banc Supreme Court panel that the state legislature “stumbled” in 2005 when it created a civil union statute but did not allow same-sex couples to actually be married under state law. Doing so, he said, marked one group of citizens as inferior and less worthy.