In the next several decades following, continued US dominance is dependent on effective education and a strong economy supporting a healthy middle class. In the next several decades after that, whatever nation/culture succeeds in expanding the scope of human civilization is going to dominate through its progeny. (In much the same way that European and in particular WASP culture that originated in England became dominant through the ascendance of the United States.)
However, the system is set up to reward those who enter the financial sector, with its tendency towards rent seeking, and the realm of law/politics, which tends to engender a viewpoint somewhat distant from the first principles that govern reality.
China, with its largely technocratic leadership, and with its pent up desire to express its pride and prowess as a civilization-state may well have the means, knowledge, and impetus to engage in such an expansion of scope. This would be the smart strategic move -- instead of directly challenging the US for power on Earth, they would expand into an even larger context.
Another beauty of such a strategy: the entrenched short-term interests of the US military industrial complex might well assist them in gaining an insurmountable lead by staying fat and happy in their status quo.