When Section 3 of DOMA (the portion prohibiting the Federal government from recognizing same sex marriages) was overturned, it was partially on a Tenth Amendment argument.
It was in overturning Section 2 of DOMA (the portion allowing States not to recognize same sex marriages performed in other States) that the Supreme Court recognized marriage rights as something which could not be restricted on the basis of the sex of the participants.
I am not certain you could construct an argument that would allow the Supreme Court to overturn Section 2 of DOMA without also declaring all State laws unconstitutional; once the Supreme Court recognized that right, the 14th Amendment applies.
When Section 3 of DOMA (the portion prohibiting the Federal government from recognizing same sex marriages) was overturned, it was partially on a Tenth Amendment argument.
It was in overturning Section 2 of DOMA (the portion allowing States not to recognize same sex marriages performed in other States) that the Supreme Court recognized marriage rights as something which could not be restricted on the basis of the sex of the participants.
I am not certain you could construct an argument that would allow the Supreme Court to overturn Section 2 of DOMA without also declaring all State laws unconstitutional; once the Supreme Court recognized that right, the 14th Amendment applies.