It's not a declaration of states' rights.
It was written to encourage the passage of a new, more powerful national government -- the Constitution.
To get its meaning, you have to think about the TIMING & PURPOSE of this statement.
People were nervous about assigning power.
This was an attempt to calm fears. AND...
Some people saw their colony as something akin to a nation-state.
In that setting, a nat'l gov't would ALWAYS come in 2nd concerning personal loyalties.
It had to stand up against the states.
Come on! Don't worry about this new strong national government! States have the balance of power!
Federalism
The idea that state governments & the nat'l gov't would share power--a deliberate ambiguity at the center of the Constitution proposing a kind of dual loyalty.
That deliberate ambiguity of federalism can be handy.
It can also cause conflict.
We're seeing in real time the clash bet. state & nat'l political power.
Of course, the Constitution plays a role in mediating this.
If we adhere to it