"the diffusion of governmental powers helps to maximize personal liberty."

Andrew Napolitano writes at Newsmax about sanctuary cities,

...The high court has also prohibited the federal government from "commandeering" the states by forcing them to work for the feds at their own expense by actively enforcing federal law. As Ronald Reagan reminded us in his first inaugural address, the states formed the federal government, not the other way around. They did so by ceding 16 discrete powers to the federal government and retaining to themselves all powers not ceded.

If this constitutional truism were not recognized or enforced by the courts, the federal government could effectively eradicate the sovereignty of the states or even bankrupt them by forcing them to spend their tax dollars enforcing federal law or paying for federal programs.

Thus the Trump dilemma. He must follow the Constitution, or the courts will enjoin him as they have his predecessor. He cannot use a stick to bend the governments of sanctuary cities to his will, but he can use a carrot. He can ask Congress for legislative grants of funds to cities conditioned upon their compliance with certain federal immigration laws.

All of this is part of our constitutional republic. By dividing powers between the feds and the states — and by separating federal powers among the president, Congress and the courts — our system intentionally makes the exercise of governmental power cumbersome by diffusing it. And since government is essentially the negation of freedom, the diffusion of governmental powers helps to maximize personal liberty.

Read more here.