If somebody knocks on your door and wants to enter your home (for whatever reason) you are faced with a decision process based, in part, on your ability to suss out why you DO or DO NOT allow entrance.
"I'm being stalked by a madman--please let me hide inside" would be a strong emotional reason."
"I'm with a group of Jehovah's Witnesses, we want to brainwash you."
That would be a religious reason. :)
Consider this is a question of SORTING alternatives.
An infinite number of situations may apply depending on how you frame the situation.
You are safe in your home UNTIL faced with the knock on the door.
At least one thing is clear.
By knocking on your door the person who wants to enter your house respects you enough to ask for a hearing and allows you the opportunity to decide based on merit.
What if that person did NOT KNOCK?
What if they sneaked in by opening a bedroom window?
A and B are framing devices for a basic decision.emotionally and intellectually.
Knocking vs sneaking in is a game-changing alternative, right?
IMMIGRATION is about RULES or NO RULES.
Knocking and saying "Yes or No" based on merit...or dealing with the stranger in your bedroom now that they're already inside without permission.
To make this otherwise is unnecessarily puzzling (i.e. Political)