Unfortunately money is the one who is leading the world one way or another. There is no politician or the party who can run without the money in the background and non of the "donations" are for free. When the certain laws needs to be accepted or the decisions needs to be taken that are in the favour of the certain ... (add by your imagination) than the payback time comes in play. You can observe that in any country, and if you take a look for instance  just how many registered lobbyist are for instance in EU parliament than you can get the bigger picture.