Mercantilism is the use of the state to fulfill one's personal objectives and self-interest. The use of the state, conflating private with public, allows the individual or small group to obtain clout that would otherwise not be feasible.
Mercantilism, the realizing of private goals for individuals or small groups through public means, has a long and ancient history, doubtless as long as humankind itself. From the beginning of the Neolithic period when humankind invented cities, humans sought mercantilist advantage.
Wherever there have been seats of power, there has been mercantilism, which eventually corrodes the process of the state and infuriates its citizens. The American exception was set up to counteract mercantilism by diffusing power in such a way that there would be no one place that a mercantilist entity could find a forceful enough lever of power to pull.
But over time the American system's power has been concentrated, nonetheless. Individuals running for federal and even state office are now willing to spend hundreds of millions of dollars to gain access to concentrations of power.
Of course, America is not alone in its concentrations of power in the modern age. The European Union has concentrated power extensively at the top and so has China. Each of these modern states is in its own way an invitation to mercantilism. In fact, one could say that an energetic power elite, behind much of the organization of great Western states, has created these systems in this matter so as to enhance mercantilist convenience.
The most prominent modern mercantilist movement, of course, is the long-term effort by the power elite to utilize Western governments for any one of a number of global promotions. Perhaps the strongest of these is the central banking promotion itself, which combines every aspect of public power with private banking.
The power elite, the larger monetary elite and the public bureaucracy have all combined to create the central banking dominant social theme. The most powerful example of this theme or meme is the US Federal Reserve, which is in every way a mercantilist endeavor – conflating the public good with private interests.
Run by the elite, developed secretly by the elite, the Fed poses as a public benefit when in fact its decisions are made by a handful of private men and the money it prints out of thin air must necessarily benefit the "powers that be" that created the Fed in the first place. It may be that historians look back and declare that the 20th century and parts of the 21st are to be known as the "Mercantilist Era."