Studies have shown that when test subjects are given a small gift of minimal value, they are statistically more likely to comply with subsequent requests made by the giver, even if the secondary request is significantly more valuable. For example: if the subject was given a free soft drink in the beginning of the evening, they were much more likely to buy raffle tickets from the person who gave them that drink, than were subjects who had not been offered anything. This principle also applies to non-physical gifts as well, such as time volunteered. Psychologists refer to this instinct as the reciprocity principle.
Among social species, reciprocity facilitates the distribution of effort and resources within a group, and provides a natural safety net. If a member of a pack or a tribe brings home food on a particular day, and they share that food with the other members, the reciprocity instinct ensures that they will be fed by others in the future. For over 300,000 years this was the primary form of exchange within human groups.
At the civilization scale, the reciprocity instinct has been hijacked. Repaying feels like a moral duty even if the gift is artificial. A fractional reserve loan still binds.
In politics, strategic gift giving is institutionalized. Running for office is expensive. To compete, one must advertise, organize events, pay staff, and travel extensively. Wealthy candidates may be able to fund these activities out of pocket, but most politicians rely on outside support. While outright bribery is technically illegal, and political donations are regulated, corporations and well heeled special interest groups always find loopholes which enable them to line influential pockets (PACs and Super PACs are contemporary examples). Ordinary citizens cannot compete in this arena.
These contributions create a debt which can be called in at a later date. Explicit agreements are unnecessary. The psychological bond is sufficient.
Corporations treat this exchange like a cost of doing business. Donations are investments towards friendly policies, lucrative contracts, a blind eye when it really counts.
In this context it should be clear that most so called “democracies” aren’t democratic at all. Most aren’t even functional republics. The term plutocracy would be more fitting; a pay to play puppet show by any other name.