Legally. Illegally, there's still quite a number of options, including a fair number of non-violent ones (since we have people here who appear to be concerned about gun violence).
Correct, I'm not assert that 'legality' alters the fabric of reality so as to compel only action that comports with what is legal. But doing something illegal is not subject to 'leeway', you're breaking the law. Unless you're arguing that 'leeway' simply encompasses any action that could be undertaken by a being with free will, which I guess I can get on board with.
But it didn't fail because it was illegal, it failed merely because FDR didn't get enough votes. This remains a ready path for someone who already controls two branches of government to control the last.
Had it passed, it could have been declared illegal by the court. That was a confrontation that did not actually occur. The FDR packing plan only supports an assertion that it has been tried unsuccessfully in the past.
Given that every US citizen is responsible for upholding the US Constitution, that implies legally leeway in interpreting it as well.
Nope. You can file a court challenge if you want, but that's all the 'leeway' a US citizen gets in going against something that has been ruled on point by SCOTUS.
And what happens when the Supreme Court makes unconstitutional decisions? This is not a hypothetical situation. It's not that hard a thing to stack with people who don't have an interest in fulfilling the job description and that has been attempted.
I'm confused. You said it isn't hard to stack SCOTUS with people who don't have an interest in fulfilling the job description, then you link to an effort to do that which failed. SCOTUS appointment procedure as it stands is as close to allowing the democratic majority to influence the judiciary as it should probably get. People don't just 'get in'. Look at the stinkers Bush floated by Congress before arriving at Roberts.
And, again, when SCOTUS says it, it is law, and Constitutional. If you have a problem with a SCOTUS decision, then you can talk to your congress critter about changing the law or amending the Constitution. That is what you can do when SCOTUS does something that -you- disagree with, but SCOTUS cannot make an unconstitutional decision, by its very nature. Been that way since Marbury v. Madison.
Any given program will expand to fill available memory.