I understand “Unalienable Rights” to mean that we can’t be alienated from them.
Exactly!
There’s a worldview and religious/theological assumption involved with “unalienable”.
For a right to be “innate” and unalienable, there has to be an Objective Source of those rights. An Ultimate Authority.
Now, leftism/liberalism is simply the political expression of humanism, which rejects the Divine in favor of an “ultimate authority” being of human origin. And, since that authority ultimately comes from the ability to force others to comply, their theology points to government as the source of rights.
It makes sense, but you can’t make them understand “unalienable rights” when their basis of truth is Humanism.