Various cities have announced plans to boycott the state of Arizona, in one way or another, in order to protest its immigration policy. One question I have not seen discussed is whether such boycotts raise constitutional issues. In the U.S. system, cities and counties are, legally speaking, creations of the states that contain them. It would seem to follow that actions of, say, the city of San Francisco count as actions of the state of California. I am not a constitutional scholar, but it is my understanding that the Constitution does not permit states to impose tariffs or similar restrictions on trade with other states.
A quick glance through the document finds that:
"The Citizens of each State shall be entitled to all Privileges and Immunities of Citizens in the several States."
"No Tax or Duty shall be laid on Articles exported from any State."
"No Preference shall be given by any Regulation of Commerce or Revenue to the Ports of one State over those of another: nor shall Vessels bound to, or from, one State, be obliged to enter, clear, or pay Duties in another."
I am not sure whether any of those, or something else I missed, has the implication I described, although the last one comes close if "ports" is broadly defined.
If I am correct, would a state whose officials promoted a boycott of another state be in violation?