"No Person shall be a Senator who shall not have attained to the Age of thirty Years, and been nine Years a Citizen of the United States, and who shall not, when elected, be an Inhabitant of that State for which he shall be chosen." -- U.S. Constitution, Article I, Section 3, Clause 3
Every once in a while we get to see a politician jump across state lines to take advantage of an open Senate or House seat -- Hillary Clinton's successful senatorial bid in New York has been a high-profile recent occurrence.