The Collaborative International Dictionary of English v.0.48:

Barnstorm \Barn"storm`\, v. i. & t. [Barn + storm, v.]
   1. To travel from place to place, making brief stops.
      [PJC]

   2. To fly an airplane from place to place, usually at small
      airports, doing flying stunts or flying passengers for
      sightseeing, for the purpose of earning money.
      [PJC]

   3. to tour the country to solicit votes.

   Syn: whistlestop.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

barnstorm
    v 1: appear at county fairs and carnivals as a stunt flier and
         parachute jumper
    2: tour the country making political speeches, giving lectures,
       or presenting plays; "The presidential candidates are busy
       barnstorming this month"