Source, at around 5:25: Justice John Paul Stevens with interviewer Stephen Colbert
[1.] Some people have different rights than others do.
=> 2. Some people have different rights than others do have different rights.
I guess the meaning of 1 as: 3. Some people's rights differ from other people's rights.
I also guess that Justice Stevens is using verb phrase ellipsis. Yet completion of the ellipsis in 1 produces 2, which doesn't sound correct? So how does 1 mean exactly 3?
The word "different" is an adjective formed from the verb differ. The verb "derails" when it is turned into an adjective and made part of an object phrase of the verb 'to have'. Consider the progression below.
Person A's set of rights differs from Person B's set of rights. ( The two sets are not identical.)
Person A's set of rights is different from Person B's set of rights.
Person A has a different set of rights than Person B does|has.
Person A has different rights than Person B does|has.
Some people have different rights than other people do|have.
The verb differ is a predicate applied to the comparands. They differ. They are different. When it becomes an adjective (different rights) that inheres in only one of the comparands, and that phrase in turn is made the object of 'to have' (have different rights) the predicate gets all tangled up with 'have'.
