Lex iniusta non est lex: An unjust law is no law at all.
Can we use that somehow?
The problem there being they will claim said law isn’t unjust.
Some German courts have invoked the concept on occasion. I would really love to see US courts rule that any criminal law that is facially and obviously unjust (not merely a bad idea, or bad law), regardless of any government power it claims to rely on, should be declared unconstitutional as a violation of the 8th Amendment.
Isn’t that what jury nullification is?