People who do this are just trying to buy access in support of their personal business interests, usually to procure favorable regulatory treatment that allows them to gain the corner a certain market.
In terms of political parties themselves, they are just part of the strategy Washington uses to maintain control over the people. Create the illusion of democracy, freedom and free market economics, all while running a tightly controlled economic and political regime, where most of the spoils go to the well-connected at the expense of everyone else, who have to deal with declining wages, higher costs of living, and higher taxes, even as the people get lesser services.
All that's required to achieve this control is to convince voters that one political party has all of the answers, while the other has caused the problems.
Accordingly, Americans will continue to vote for candidates from one of the two corrupt parties in Washington. Thus, Americans get the same results regardless which party is in power. This is why income disparities continue to grow, why our industrial cities are becoming wastelands, why our private and public debt loads continue to grow regardless of who's in power.
When it comes to trade policy, monetary policy and foreign policy, both parties always agree. They are going to ship US jobs overseas, allow the Federal Reserve and Wall Street crime syndicate to commit massive fraud, and fight unnecessary wars to support this unsustainable monetary structure. Regardless who they vote for, we always lose. Thus, heading to the voting booth to support either party serves no purpose other than to endorse those policies.
On rare occasion when fraud has been exposed, none of the establishment crime bosses goes to jail. At best, one or two scapegoats are pulled from the bottom of the criminal food chain to serve as the "fall guy." But even the fall guys come out of the deal shining. In most cases, after a couple of years in club fed, they are rewarded by their colleagues for taking the heat.
Incredible how easy it is to play people against each other. Corruption is the main problem.