If the NJSC abides by the written law, which is very clear, then you are correct. In that case it is just a state deciding to follow it's own laws. Otherwise, it is an illegal attempt to change the outcome of an election that has national impact. It is not just a state issue when the openly stated purpose of all of this is to keep the democrat majority in the Senate.
Would you see the national impact if NJ simply passed a law requiring all it's US senators to be democrats?