再來看看第三個論點：依據「平等保障條款」(the Equal Protection Clause)，同性伴侶亦應同等地享有婚姻權。

有趣的是，大法官 Anthony Kennedy 在決議文裏，不是以「平等保障條款」作為一個獨立的法律基礎，而是將它與「正當程序條款」作個連結，交互引用。這是什麼意思呢？其實，大法官 Anthony Kennedy 於決議文裏，說得不夠清楚，這同時也成為首席大法官 John Roberts 於反對意見書裏攻擊的重點。

先來看看大法官 Anthony Kennedy 是怎麼說的：「正當程序條款和平等保障條款之間，具有一定的關聯性，但它們各自仍保有自己的特質。隱含於自由權裏的權利，和受到平等保障條款保護的權利，二者之本質不同、範圍亦不盡然一致，但在若干案例中，其一可能會對另一者產生指導作用。」 (The Due Process Clause and the Equal Protection Clause are connected in a profound way, though they set forth independent principles. Rights implicit in liberty and rights secured by equal protection may rest on different precepts and are not always co- extensive, yet in some instances each may be instructive as to the meaning and reach of the other.) 「透過這兩個原則間之交互作用，可以讓我們更了解自由的意義。」 (This interrelation of the two principles furthers our understanding of what freedom is and must become.)

如何透過這兩個原則的交互作用，究顯出「自由」之應有 (is) 及當有 (must become) 之意義呢？大法官 Anthony Kennedy 舉了幾個例子。其一是於 Loving 一案，美國聯邦最高法院表示：禁止不同種族之間通婚，毫無疑問地，這是對於婚姻自由的限制，違反了平等保障條款。 (“There can be no doubt that restricting the freedom to marry solely because of racial classifications violates the central meaning of the Equal Protection Clause.” )

另一個例證，同時也出現在大法官第748號解釋理由書的是：不承認同性婚姻之合法性，將使得同性伴侶無法和異性伴侶一樣，平等地享有婚姻所帶來的利益和保障。 (Here the marriage laws enforced by the respondents are in essence unequal: same-sex couples are denied all the benefits afforded to opposite-sex couples and are barred from exercising a fundamental right.)

最後，大法官 Anthony Kennedy 於結論中指出：「婚姻權乃是基本權，同時也是自由權的固有內涵。並且，依據正當程序條款及平等保障條款，不得將同性伴侶排除在外，以免侵害其婚姻權及自由權。」 (These considerations lead to the conclusion that the right to marry is a fundamental right inherent in the liberty of the person, and under the Due Process and Equal Protection Clauses of the Fourteenth Amendment couples of the same-sex may not be deprived of that right and that liberty.)