My rationale for court first is that secession is the "nuclear option" and should be a last resort, not a first move.
If your goal is to have the south secede from the Union and are looking for any excuse to do so, then yes, by all means you could secede if Hillary unilaterally declared the Second Amendment null and void.
If, however, your goal (as is mine) is to preserve, protect, defend, and expand our God given Second Amendment rights, court would be your first option to have the unconstitutional actions of Hillary overturned, just as the courts overturned Obama's executive order on suspending deportations.
OK, I see why we have a problem, you are thinking a second Southern States seceding, I am not, I am only concerned with secession for Maine.
We have no inclination to sue, we know we do not have the votes, so...................