It may not have been clear from a legal view, but they surely had even higher obligations to keep faith with the Republic. They pledged a solemn faith and violated it for light and transient reasons. They had other options to address their concerns and instead choose to give a unilateral middle finger to the legacy of the Framers because they swallowed their own macho propaganda that no one would dare stop them. They were arrogant, self-absorbed fools.
In my book, that is far more egregious than any legal violation.