The Constitution’s guarantee of equality “must at the very least mean that a bare congressional desire to harm a politically unpopular group cannot” justify disparate
treatment of that group. Department of Agriculture v. Moreno, 413
U. S. 528, 534–535. DOMA cannot survive under these principles.
Its unusual deviation from the tradition of recognizing and accepting
state definitions of marriage operates to deprive same-sex couples of
the benefits and responsibilities that come with federal recognition of
their marriages. This is strong evidence of a law having the purpose
and effect of disapproval of a class recognized and protected by state