Depends on one's perspective. From the perspective of racist segregationists in the Deep South, the Feds were stepping in to deny them their rights to free association. From the perspective of just about everyone else, the Feds were stepping in to grant rights to racial minorities to be treated equally before the law.

(And I'm not a lawyer either, so my reasoning is also pretty suspect.)

I agree that passing a law is certainly stronger than passing a non-binding resolution ... but if the Feds step in and nullify the law, they both end up in the same place. Doesn't mean it shouldn't be done, of course ... but I'm not going to start celebrating just yet.