On a related matter, courts have also held that not only are unconstitutional laws null and void from the moment they supposedly begin, but also that you have every right to defend yourself against unlawful force and attempted murder. The fact that the government, through its agents, may be your attacker is immaterial:

"Citizens may resist unlawful arrest to the point of taking an arresting officer's life if necessary."
Plummer v. State, 136 Ind. 308 (1893)

This premise was upheld by the Supreme Court of the United States when the court stated: "where the officer is killed in the course of the disorder which naturally accompanies an attempted arrest that is resisted, the law looks with very different eyes upon the transaction, when the officer had the right to make the arrest, from what it does if the officer had no right. What might be murder in the first case might be nothing more than manslaughter in the other, or the facts might show that no offense had been committed." John Bad Elk v. U.S., 177 U.S. 529, (1900).

"An arrest made with a defective warrant; or one issued without affidavit; or one that fails to allege a crime is without jurisdiction, and one who is being arrested, may resist arrest and break away. If the arresting officer is killed by one who is so resisting, the killing will be no more than an involuntary manslaughter." Housh v. People, 75 Ill. 491; State v. Leach, 7 Conn. 452; State v. Rousseau, 241 P. 2d 447; State v. Spaulding, 34 Minn. 3621.

Consider the fiery end of the Branch Davidians in their home while you ponder that one.

"These principles apply as well to an officer attempting to make an arrest, who abuses his authority and transcends the bounds thereof by the use of unnecessary force and violence, as they do to a private individual who unlawfully uses such force and violence." Jones v. State, 26 Tex. App.1; Beaverts v. State, 4 Tex. App. 175; Skidmore v. State, 43 Tex. 93. 1903

"When a person, being without fault, is in a place where he has a right to be, is violently assaulted, he may, without retreating, repel force by force, and if, in the reasonable exercise of his right of self defense, his assailant is killed, he is justifiable." Runyan v. State, 57 Ind. 80; Miller v. State, 74 Ind.1.      http://freedom-school.com/frog-farm-faq.pdf