The legal power of a head of state, including the President of the United States, is both extraordinary and, at least in the U.S., little known. It may be little known in the more powerful nations of the world, but a little better known in the less powerful nations, where relationships with the more powerful nations can be more threatening. The President has a legal duty to try to prevent war against the U.S. and, for that reason, may overrule all U.S. law and courts and effectively suspend all legal rights guaranteed by the Constitution when contrary to the norms. If the President does so, impeachment may be a consequence and prison time may be imposed, but a foreign nation may have the right by law to invade and, even forcefully, give the President asylum, either elsewhere or right in the U.S. The same is largely true of all nations around the world.
Hiding this may be useful to the strength of a nation’s domestic legal system, but it may be useful for more people to understand the interplay of the norms and other bodies of law.
Overrobustness may preserve the nation’s control over its leadership, including its head of state, but it is unlawful. It may preserve democracy, political stability, and economic security. It may do all that and maybe more, although it does so illegally. The norms are supposed to govern and they do. Only the interstices may be filled by domestic law. When the law is applied that way, there is not overrobustness. When there is, overrobustness may be reflective of popular preference and of the inability of a nation to change the norms and it may be good for society, but it is unlawful. The norms rule, whether we like it or not.