Check out this Newsweek series of
articles & related videos. Every election Newsweek detaches (literally) a handful of reporters who go out onto the campaign with the candidates 24/7, but who aren't allowed to report anything until after the polls close. They get access & deep background that you can't find anywhere else.
(if nothing else, be sure to see the video clip at the top of the first page - pretty damning version of the Palin wardrobe dustup)