Senators spend a lot of their time attaching rider bills to legislation and funneling as much money as possible to their states, to the detriment of every other state. This incoming money is a major campaign gimmick (effectively buying off voters), but it does mean they have to be keyed in to state and lower level issues to know where to send the money. House members have similar concerns, but they have to demonstrate to their voters their competence in national issues every two years, meaning that their emphasis, ironically, becomes that of the "big picture".
Because House members have to run for re-election every two years, they spend a great deal of their time campaigning. They are paid less and have to constantly shell out more money on campaigns and travel. This means they are more susceptible to influence from special interests who offer them much-needed money in exchange for their votes.
