You say, "Hey, Williams, but it's the law!" In the late-1700s, the British Parliament enacted the Sugar Act, the Stamp Act and the Townshend Acts, and imposed other grievances that are enumerated in our Declaration of Independence. I'm happy that we didn't have today's Americans around at the time to bow before King George III and say, "It's the law." Respectful of the Posse Comitatus Act, President Bush has suggested that he'll ask Congress to amend the law to allow for the use of the U.S. military to enforce regional quarantines. Whether Congress amends the law or not, Bush has no constitutional authority to deploy military troops across the land. Why?
The U.S. Constitution's Article IV, Section 4 reads, "The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened), against domestic Violence." Coupled with the Tenth Amendment, "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people," this means short of an insurrection, the U.S. military must be invited by a state legislature or executive. Any federal law that violates these constitutional provisions is null and void and can only be enforced through fear, intimidation and brute military force.