The common fallacy that has continually been brought to the forefront is the idea that Arizona law has created a new law that requires immigrants to carry papers with them at all times.
From SB 1070 (Arizona Immigration Law: IN ADDITION TO ANY VIOLATION OF FEDERAL LAW, A PERSON IS GUILTY OF WILLFUL FAILURE TO COMPLETE OR CARRY AN ALIEN REGISTRATION DOCUMENT IF THE PERSON IS IN VIOLATION OF 8 UNITED STATES CODE SECTION 1304(e) OR 1306(a).
As can be seen, this law piggybacks federal code already in place. Let's see what 8 US Code 1304(e) and 1306(a) says.
8 USC 1304(e):
(e) Personal possession of registration or receipt card; penalties
Every alien, eighteen years of age and over, shall at all times
carry with him and have in his personal possession any certificate
of alien registration or alien registration receipt card issued to
him pursuant to subsection (d) of this section. Any alien who fails
to comply with the provisions of this subsection shall be guilty of
a misdemeanor and shall upon conviction for each offense be fined
not to exceed $100 or be imprisoned not more than thirty days, or
8 USC 1306(a):
a) Willful failure to register
Any alien required to apply for registration and to be
fingerprinted in the United States who willfully fails or refuses
to make such application or to be fingerprinted, and any parent or
legal guardian required to apply for the registration of any alien
who willfully fails or refuses to file application for the
registration of such alien shall be guilty of a misdemeanor and
shall, upon conviction thereof, be fined not to exceed $1,000 or be
imprisoned not more than six months, or both.
As can be clearly seen, federal law already exists which requires aliens to carry paperwork. Arizona law doesn't create that requirement, the federal government does. Arizona has expanded it to state law due to the fact the federal government has failed to live up to it's responsibilities in Arizona and securing her borders.
It is irresponsible and dishonest for protesters and pundits to pretend Arizona has established a Nazi state by requiring her citizens to "carry papers". If that part of the law is objectionable, then they should protest the federal government for redress, after all Arizona used federal code to craft it's law.