If someone passes an unconstitutional law, the reasonable response isn't to secede (which is itself unconstitutional), but to challenge it in the courts (as well as to vote out of office the legislators/executives who pushed those laws).
"Cutting off your nose to spite your face" would be the cliche here.
The courts actually ruling it unconstitutional would be a decent outcome as well. And maybe they even would with such a blatant contradiction. But if not, hopefully the incongruence would finally be explicit enough to dispel the wishful belief that the government is bound by a piece of paper.
"Cutting off your nose to spite your face" would be the cliche here.