The corporate world buys both parties, because it expects them both to faithfully do its bidding once they are in office....and they do. Whichever party the corporate world regards as more electable in any given election, that is the one they will give more money to, I would think. They are buying up future cooperation when they do so.

Obviously, they would rather bet on the horse that they think is going to win. But if they spread their bets around some, then they've got it covered either way.