You are incorrect. I will explain.

The whole sentence only makes sense if you read it in it's entirety (you know like a sentence is supposed to be read). If they were separate things as right-wing activists argue then they wouldn't be in the same sentence.

As for the rest of it if you aren't familiar with what surplusage is (how they said the entirety of the first part of the sentence is irrelevant) and how that flies smack dab into the face of the Constitution as it has been read since at the latest 1803 in Marbury v Madison then...

To show what I mean

[[A well regulated Militia, being necessary to the security of a free State, ..., shall not be infringed.]]

See now people owning arms for personal use argument doesn't work for you. You just interpret it your way because you like the right-wing activists ruling. This reading doesn't make any less sense. You don't get to just cut up a sentence to suit your views which is exactly what the right wing activists did.

It's not because if we act like they're separate things then the first part says nothing, does nothing.

[[A well regulated Militia, being necessary to the security of a free State,]]

If they were separate things this is all the first part says. It says nothing. It's surplusage. That flies in the face of the way the law (all law [except for right-wing activists who read what they want]) has been read since 1803 in Marbury v Madison.

If you read the amendment in a non-right-wing activist fashion as it was in Miller (the way it had been read in the US up until right-wing activists in 2008) it's a collective right not an individual one. Which would mean the Guard is largely what the 2nd it talking about and the Feds can't stop states from having their own militia and arming/training it.

Grammatically two separate non-linked ideas should not be contained in the same sentence without semicolons or coordinating conjunctions.